If a person is born in hindu religion, he will have some caste. And is there anything that mentioned about foreigners? There are some civilizations like babylon that started in mesopotamia, along with indus valley, and ever mixed. What caste those people come under?. Is there anything that mentioned about foreigners and other religions in our sacred texts? I know Hinduism is a way of living more than a religion! But people following a different way of living come under which caste?
How is caste determined? What we call as caste in english is called varṇa in sanskrit. One of the meanings of varṇa is color, specifically of the mind, i.e character or nature. Though birth can play a significant role in shaping up one's nature, from the point of view of Bhagavad Gita and Srimad Bhagavatam, birth does not draw a hard line on what caste a person belongs to. In fact the emphasis is clearly on guṇa (nature) and karma (activities).
Bhagavad Gita 4.13 says
According to the three modes of material nature and the work associated with them, the four divisions of human society are created by Me. And although I am the creator of this system, you should know that I am yet the nondoer, being unchangeable.
And in chapter 18 of the Gita the nature/activities of the varnas are further described as below:
Bg 18.41 — Brahmanas, ksatriyas, vaisyas and sudras are distinguished by the qualities born of their own natures in accordance with the material modes, O chastiser of the enemy.
Bg 18.42 — Peacefulness, self-control, austerity, purity, tolerance, honesty, knowledge, wisdom and religiousness – these are the natural qualities by which the brahmanas work.
Bg 18.43 — Heroism, power, determination, resourcefulness, courage in battle, generosity and leadership are the natural qualities of work for the ksatriyas.
Similarly in Srimad Bhagavatam also this topic is discussed by Sri Narada Muni in canto 7 chapter 11 . There his conclusion is:
SB 7.11.35 — If one shows the symptoms of being a brahmana, ksatriya, vaisya or sudra, as described above, even if he has appeared in a different class, he should be accepted according to those symptoms of classification.
Finally I would like to mention that regardless of what varṇa one may belong to, it is not a hindrance for attaining the Supreme Lord. This fact is mentioned by Lord Krishna in the Bhagavad Gita:
Bg 9.32 — O son of Prtha, those who take shelter in Me, though they be of lower birth – women, vaisyas [merchants] and sudras [workers] – can attain the supreme destination.
What caste do foreigners belong to?
General Perspective: Since these people do not follow the varna system of Vedic culture the terms like mleccha and yauvana are used to describe them. These terms indicate they are less than sudras. You can find these in sanskrit dictionaries like Monier or Apte. A description of these races can be found in the purport of Srila Prabhupada to Srimad Bhagavatam 2.4.18 where he connects the places outside modern India to the original Bharata Varsa using references from Mahabharata.
However when any of the foreigners take up the Vedic culture their classification wouldn't be any different than the Indian Hindus according to the Gita and Bhagavatam references above. Having a birth in different land or religion is not a barrier. This practice is prevalant in Gaudiya Vaishnava tradition where many brahmanas and sanyasins are from foriegn origin.
First of all, Caste System is a NON-HINDU, widely propagated idea of Victorian age, that is an "exaggerations" of the NON-HINDU, yet unfortunate discriminations that some Varna had to face while the oppressive Muslim regime in India.
You see, the division is called Varna System, which was NEVER birth-based actually. It was all dependent on the Guru, that individual had taken his deeksha from. (Note that, a Guru holds the highest position in a Hindu world, equivalent to Gods). In the most common case, a person's OWN father was his Guru by default. So it was customary e.g, for a son of Brahman to be a Brahman etc.
BUT, the important thing to note is that, one was ABSOLUTELY FREE to seek discipleship of any person in this world. So with the grace of a Guru, a boy born in a Shudra family could also change into a Brahman, i.e a Varna that is supposed to be seeking Brahmm, self-realization, and eventually Moksha. OR a Brahman's child can become a Shudra too, by the grace of his Shudra Guru (one who imparts "Shudra skills" in his disciples).
In all a Guru was the ONLY one, considered having the potential to "Transform" his disciple into his own self. So under a (supposedly actual) Brahman Guru who teachs skills of self-realization, all his disciples, no matter what their ethnicity or Varna are, become Brahmans themselves.
Later, indeed things degraded, and like an Avalanche, starting from Brahmans, whole Varna system eventually broke down to whats later came to be called as Caste System, by Britishers.
The ONLY thing "fixed" to any individual is his Gotra. You can not assign a Gotra to a foreign coverts to Hinduism, or in fact anyone. Its strictly birth-based. Because that are linages from the Eight Mind-born Sons of Brahma, called Gotrakarin, meaning roots of Gotras. It is (believed to be) a way to ensure no Eunuchs are born as offspring, so that their family can grow further.
NOTE: I seldom provide references in my posts when I present my views on the subject, because I think looking up to a book every time you need to think "think!", is a again NOT a Hindu trait. Vedas were in souls of ancient sages, they did not mug it up either. Reading Vedas should be a journey of Mind to soul, rather than of memory from one synapse to the other.
Mind you, that there is a difference between Vedas and books of other religion. "Vedas" are NOT "Holy" as in "Holy Bible" or "Holy Quran", but they can for sure MAKE YOU HOLY.
I think the best guess is that foreign communities that accepted Hinduism were given one caste. Were foreigners accepted in Hinduism? Let me post Vivekananda's answer to a journalist.
"I want to see you Swami", I began, "on this matter of receiving back into Hinduism those who have been perverted from it. Is it your opinion they should be received?
"Certainly", said the Swami (Vivekananda)," they can and aught to be taken."
He sat gravely for a moment, thinking, and then resumed, "Besides," he said, "we shall otherwise decrease in numbers. When the Mohammedans first came, we are said -- I think on the authority of Ferishta, the oldest Mohammedan historian --- to have been six hundred millions of Hindus. Now we are about two hundred millions. And then every man getting out of the Hindu pale is not only a man less, but an enemy the more. Again the vast majority of Hindu perverts to Islam and Christianity are perverts by the sword, or to the descendents of these. It would be obviously unfair to subject these to disabilities of any kind. As to the case of born aliens, did you say? Why, born aliens have been converted in the past by crowds, and the process is still going on. In my own opinion, this statement not only applies to aboriginal tribes, to outlying nations, and to almost all our conquerors before the Mohammedan conquest, but also to all those castes who find a special origin in the Puranas. I hold that they have been aliens thus adopted. Cermonies of expiation are no doubt suitable in the case of willing converts, returning to their Mother church, as it were; but on those who were alienated by conquest-- as in Kashmir and Nepal -- or on strangers wishing to join us, no penance should be imposed."
- Vivekananda (Complete Works V, p233, interview given in "Prabuddha Bharat", April, 1899)
Nowadays foreigners accepted into Hinduism do not have to accept any caste. Caste is a peculiar institution in India. I doubt if people like Julia Roberts who converted to Hinduism claim to be of any caste. I asked the Vice President of the Malibu Hindu temple about how they handle the gotra issue of American Hindus who offer Pujas in the temple. He told me that the temple priests do not ask American Hindus their gotra for obvious reasons and just use the term 'natural gotra' in Pujas offered by them.