This question is maybe, as a conspiracy. I thing, that some people of You won’t be happy with My opinions, but those are just My opinions not created just in My head, but also by other people too.
I have heard, that Indo-Arians were also white, like We are. Also I have heard some strange informations, that those from 4th category class in India was a dark people, first people, which were inhabited India. There was also some interview, when one anthropologist says, that there are also white Indians, not only those dark. It was intermarriages between Indo-Arians, and Dravidians. Yes, Dravidians were amongst first, who came to India many thousand years ago.
I have heard also, that Tamil was before Sanskrit. Also, many Tamil people are against Indo-Arian people. It means, that Dravidians were first?
Yes, there are some archeological evidences. You can find It on the internet, for example in Wikipedia. A big example is Harappan civilisation.
Nowadays, mostly Indo-Arians lives in northern India and Dravidians in southern India. But why are Dravidian people against Indo-Arian? Maybe there were some racial things in Indo-Arian group of people against Dravidians? When I have combined those informations mentioned abowe, I am worried, that yes. I think, that Dravidians were enslaved by Indo-Arians. Also, Dravidian haplo group is similar to those people living in Indonesia, or oceanian islands. But, there is big hope. Many of those people were in great classes or casts. So, how was It?