First understand the meaning of the word Guru in Sanskrit tradition, Guru has to be a realized being. It's not possible for ordinary being to know if a person is realized or not.

So the safest bet is to know how integrated the person is to Shastras and their Guru parampara. Although, there are many great exceptions like Sri Ramana Maharshi who don't have a Guru parampara and don't have a successor.

A Guru has to evaluated on the 4 parameters:

1. ShastraPramana: The original scriptures of the tradition of the Guru parampara. Are the teachings and claims made by Guru backed by Shastras ? How integrated the Guru is to those Shastras  ? Are the disciples encourages to read and follow those original scriptures  ?

2. Apta Pramana: If the Shastras work then there must be other Gurus i.e. realized masters in the present and past who would have "realized" the experience mentioned in Shastras and would have written commentaries based on their self realization. (Think of them like experiments that have been replicated by other "experts" based on the original publication (shastras))

3. Atma Pramana: The self experience of the Guru itself. Are they in sync with the Apta Pramana and Shastra Pramana i.e. Is Guru able to replicate the results specified by Shastras and do they correlate the results with other publications  ?

4. Sakshi Pramana: The experience of disciple itself. Can the experience of disciple itself conform to the results recorded as the result of ShastraPramana, AptaPramana and AtmaPramana.

This system is a very vigorous system of evaluation. It is often very very difficult to find a Guru who passes the 4 parameters listed above. But if you find one who passes on all counts immediately go to him/her.

Till one finds a such a Guru its best to follow an Acharya who is integrated to Shastras. Every Kriya suggested by the Acharya has to be backed up the "Shastra" and insist on producing the original Sanskrit verse.

For eg, if one has to bend the body in a certain way for Yoga it has to be based on the original Sanskrit verse. If one has to put certain material into Homa, it has to be specified in the Sanskrit verse.

Thankfully, there are many traditional Acharyas who follow the Shastras and more then glad to produce the original Shastras.

Even among Gurus, there are different Gurus who can "transmit" different areas of Shastras. When the Guru thinks the disciple is ready and has nothing more to add then Guru send the disciple to the "next" Guru. This process goes on till disciple is sent to the Sadguru. (Sadguru, as per Shastras, its a very specific Sanskrit term)

References:

1. http://books.nithyanandatimes.org/wp-content/uploads/sites/5/2016/12/NithyanandaYogaMobileRelease-Reduced.pdf (Page 7)

2. Sastra Praman, Apta Pramana and Atma Pramana: A Dialogue between Swami Nithyananda and Rajiv Malhotra http://hinduismnow.org/blog/2017/02/26/sastra-praman-apta-pramana-atma-pramana-dialogue-swami-nithyananda-rajiv-malhotra/

3. "A Discussion with Nithyananda: on God vs. Sadashiva, Why Wear Gold, Attacks against Hinduism & More" https://www.youtube.com/watch?v=SNAHZpRl3go ... original video of the transcript in 2

First, understand the meaning of the word Guru in Sanskrit tradition, Guru has to be a realized being. It's not possible for ordinary beings to know if a person is realized or not.

So the safest bet is to know how integrated the person is to Shastras and their Guru parampara. Although, there are many great exceptions like Sri Ramana Maharshi who don't have a Guru parampara and don't have a successor.

A Guru has to be evaluated on the 4 parameters:

1. ShastraPramana: The original scriptures of the tradition of the Guru parampara. Are the teachings and claims made by Guru backed by Shastras ? How integrated the Guru is to those Shastras? Are the disciples encourages to read and follow those original scriptures?

2. Apta Pramana: If the Shastras work then there must be other Gurus i.e. realized masters in the present and past who would have "realized" the experience mentioned in Shastras and would have written commentaries based on their self-realization. (Think of them like experiments that have been replicated by other "experts" based on the original publication (shastras))

3. Atma Pramana: The self-experience of the Guru itself. Are they in sync with the Apta Pramana and Shastra Pramana i.e. Is Guru able to replicate the results specified by Shastras and do they correlate the results with other publications?

4. Sakshi Pramana: The experience of disciple itself. Can the experience of disciple itself conform to the results recorded as the result of ShastraPramana, AptaPramana, and AtmaPramana.

This system is a very vigorous system of evaluation. It is often very very difficult to find a Guru who passes the 4 parameters listed above. But if you find one who passes on all counts immediately go to him/her.

Till one finds such a Guru it's best to follow an Acharya who is integrated to Shastras. Every Kriya suggested by the Acharya has to be backed up the "Shastra" and insist on producing the original Sanskrit verse.

For eg, if one has to bend the body in a certain way for Yoga it has to be based on the original Sanskrit verse. If one has to put certain material into Homa, it has to be specified in the Sanskrit verse.

Thankfully, there are many traditional Acharyas who follow the Shastras and more than glad to produce the original Shastras.

Even among Gurus, there are different Gurus who can "transmit" different areas of Shastras. When the Guru thinks the disciple is ready and has nothing more to add then Guru sends the disciple to the "next" Guru. This process goes on till the disciple is sent to the Sathguru. (Sathguru, as per Shastras, is a very specific Sanskrit term)

References:

1. http://books.nithyanandatimes.org/wp-content/uploads/sites/5/2016/12/NithyanandaYogaMobileRelease-Reduced.pdf (Page 7)

2. Sastra Praman, Apta Pramana, and Atma Pramana: A Dialogue between Swami Nithyananda and Rajiv Malhotra http://hinduismnow.org/blog/2017/02/26/sastra-praman-apta-pramana-atma-pramana-dialogue-swami-nithyananda-rajiv-malhotra/

3. "A Discussion with Nithyananda: on God vs. Sadashiva, Why Wear Gold, Attacks against Hinduism & More" https://www.youtube.com/watch?v=SNAHZpRl3go ... original video of the transcript in 2

First understand the meaning of the word Guru in Sanskrit tradition, Guru has to be a realized being. It's not possible for ordinary being to know if a person is realized or not.

So the safest bet is to know how integrated the person is to Shastras and their Guru parampara. Although, there are many great exceptions like Sri Ramana Maharshi who don't have a Guru parampara and don't have a successor.

A Guru has to evaluated on the 4 parameters:

1. ShastraPramana: The original scriptures of the tradition of the Guru parampara. Are the teachings and claims made by Guru backed by Shastras ? How integrated the Guru is to those Shastras ? Are the disciples encourages to read and follow those original scriptures ?

2. Apta Pramana: If the Shastras work then there must be other Gurus i.e. realized masters in the present and past who would have "realized" the experience mentioned in Shastras and would have written commentaries based on their self realization. (Think of them like experiments that have been replicated by other "experts" based on the original publication (shastras))

3. Atma Pramana: The self experience of the Guru itself. Are they in sync with the Apta Pramana and Shastra Pramana i.e. Is Guru able to replicate the results specified by Shastras and do they correlate the results with other publications ?

4. Sakshi Pramana: The experience of disciple itself. Can the experience of disciple itself conform to the results recorded as the result of ShastraPramana, AptaPramana and AtmaPramana.

This system is a very vigorous system of evaluation. It is often very very difficult to find a Guru who passes the 4 parameters listed above. But if you find one who passes on all counts immediately go to him/her.

Till one finds a such a Guru its best to follow an Acharya who is integrated to Shastras. Every Kriya suggested by the Acharya has to be backed up the "Shastra" and insist on producing the original Sanskrit verse.

For eg, if one has to bend the body in a certain way for Yoga it has to be based on the original Sanskrit verse. If one has to put certain material into Homa, it has to be specified in the Sanskrit verse.

Thankfully, there are many traditional Acharyas who follow the Shastras and more then glad to produce the original Shastras.

Even among Guru, there are different Gurus who can "transmit" different areas of Shastras. Generally, these Guru send the disciple to "next" Guru when the disciple is ready. The process goes on across births till disciple finds the Sadguru. (Sadguru, as per Shastras, its a very specific Sanskrit term)

References:

1. http://books.nithyanandatimes.org/wp-content/uploads/sites/5/2016/12/NithyanandaYogaMobileRelease-Reduced.pdf (Page 7)

2. Sastra Praman, Apta Pramana and Atma Pramana: A Dialogue between Swami Nithyananda and Rajiv Malhotra http://hinduismnow.org/blog/2017/02/26/sastra-praman-apta-pramana-atma-pramana-dialogue-swami-nithyananda-rajiv-malhotra/

3. "A Discussion with Nithyananda: on God vs. Sadashiva, Why Wear Gold, Attacks against Hinduism & More" https://www.youtube.com/watch?v=SNAHZpRl3go ... original video of the transcript in 2

First understand the meaning of the word Guru in Sanskrit tradition, Guru has to be a realized being. It's not possible for ordinary being to know if a person is realized or not.

So the safest bet is to know how integrated the person is to Shastras and their Guru parampara. Although, there are many great exceptions like Sri Ramana Maharshi who don't have a Guru parampara and don't have a successor.

A Guru has to evaluated on the 4 parameters:

1. ShastraPramana: The original scriptures of the tradition of the Guru parampara. Are the teachings and claims made by Guru backed by Shastras ? How integrated the Guru is to those Shastras ? Are the disciples encourages to read and follow those original scriptures ?

2. Apta Pramana: If the Shastras work then there must be other Gurus i.e. realized masters in the present and past who would have "realized" the experience mentioned in Shastras and would have written commentaries based on their self realization. (Think of them like experiments that have been replicated by other "experts" based on the original publication (shastras))

3. Atma Pramana: The self experience of the Guru itself. Are they in sync with the Apta Pramana and Shastra Pramana i.e. Is Guru able to replicate the results specified by Shastras and do they correlate the results with other publications ?

4. Sakshi Pramana: The experience of disciple itself. Can the experience of disciple itself conform to the results recorded as the result of ShastraPramana, AptaPramana and AtmaPramana.

This system is a very vigorous system of evaluation. It is often very very difficult to find a Guru who passes the 4 parameters listed above. But if you find one who passes on all counts immediately go to him/her.

Till one finds a such a Guru its best to follow an Acharya who is integrated to Shastras. Every Kriya suggested by the Acharya has to be backed up the "Shastra" and insist on producing the original Sanskrit verse.

For eg, if one has to bend the body in a certain way for Yoga it has to be based on the original Sanskrit verse. If one has to put certain material into Homa, it has to be specified in the Sanskrit verse.

Thankfully, there are many traditional Acharyas who follow the Shastras and more then glad to produce the original Shastras.

Even among Gurus, there are different Gurus who can "transmit" different areas of Shastras. When the Guru thinks the disciple is ready and has nothing more to add then Guru send the disciple to the "next" Guru. This process goes on till disciple is sent to the Sadguru. (Sadguru, as per Shastras, its a very specific Sanskrit term)

References:

1. http://books.nithyanandatimes.org/wp-content/uploads/sites/5/2016/12/NithyanandaYogaMobileRelease-Reduced.pdf (Page 7)

2. Sastra Praman, Apta Pramana and Atma Pramana: A Dialogue between Swami Nithyananda and Rajiv Malhotra http://hinduismnow.org/blog/2017/02/26/sastra-praman-apta-pramana-atma-pramana-dialogue-swami-nithyananda-rajiv-malhotra/

3. "A Discussion with Nithyananda: on God vs. Sadashiva, Why Wear Gold, Attacks against Hinduism & More" https://www.youtube.com/watch?v=SNAHZpRl3go ... original video of the transcript in 2