Hinduism Stack Exchange is a question and answer site for followers of the Hindu religion and those interested in learning more about Hinduism. It only takes a minute to sign up.
Sign up to join this community
the forehead mark or Namam is different for the two subsects.
What is the difference between Thenkalai and Vadakalai sects of Sri Vaishnavism?
states that they also have doctrinal differences.
But there is intermarriage between them - can an Iyengar change his/her Kalai for this reason or out of free choice?
There is no "becoming" a Vadakalai (V) or Thenkalai (T). These categories are all labels that loosely indicate what a person theoretically believes in. I said theoretically because nobody perfectly follows all beliefs in practice.
The most important philosophical difference between these two groups is in the nature of the individual jIva's efforts towards attaining liberation. V-s emphasize the role of individual effort whereas T-s emphasize the role of divine grace. However most people calling identifying themselves as one of these two groups likely know nothing about this topic.
On a more practical note, the most conspicuous difference between a T and a V is the shape of the Urdhvapundram sported. However most people who call themselves one of the above two rarely wear these on a daily basis.
There are other differences between the two groups, and there are people of one group who partially follow some practices of the other.
Intermarriage between the two communities has been happening since time of Sri Ramanuja vide the Guruparamparas.
So I hope you understand that the question really is moot. If you want to know if a T or V wishes to change their opinion on a certain issue, nobody is stopping them from changing their opinion.
There is really no "initiation" ceremony to "become" a "T" or "V". There is a "samashrayana / pancha-samskara" ritual which is a prerequisite (additional to the Upanayana for men and wedding for women) from the Pancharatra Agamas in order to perform Vaidika Karmas. This is because all offerings in Vaidika Karmas are first offered to Vishnu and worship of Vishnu has the pancha-samskara ritual as a prerequisite. This ritual is common to both groups. It could be called an "initiation" but it is certainly not an "initiation into the specific group".
