There are nothing called as Races based on Caste and Religion in India. Indians are basically Indians. All our life we are hearing that someone is a North Indian and someone is South India and caste-ism always played a role in India. I always wanted to learn about Ancient Indians as that gives us an idea of the habits of India. What matters most is all of Indians are found to have similar Genetic markers which means that a person born in New Delhi cannot say whether his ancestors came from Hyderabad or a person in Tamil Nadu cannot say that if his ancestors were distinctly similar to the genetic mark up of Bengalis. What matters the most as we create a linguistic and secular divide in our country based on caste, we tend to forget that Ancient India from 0 CE onward to the present era have become racists as a direct change of climate along the Tropic of Cancer.All castes are a direct gradient of the change in patterns and our eating habits. However if we look inwards we all belong to a migrant population that underwent a severe mixing that is why our population grew to this extent. The present genetic markers have been able to make our ancestral lineage which was a mixture of polytheistic customs because of Iranians and Zoroastrians. South Asia is a mix of four groups of people who have settled at various points in Time. Looking at the link makes it easier to understand
I would ask people to read
The peopling of South Asia: an illustrated guide
There were four major migrations into India
Ancient Migrants who came to South Asia and stayed there (Proto Asians/Eurasians) - 50kya Neolithic Farmers from Iran - 10kya - 7kya (The world's first farmers were surprisingly diverse) East Asian expansion from the Northeast into India (Y-chromosome diversity suggests southern origin and Paleolithic backwave migration of Austro-Asiatic speakers from eastern Asia to the Indian subcontinent) Yamnaya (PIE) expansion from the Pontic Steppe into India. They are mix of ANE (Ancestral North Eurasians) plus (Caucasian Hunter gatherers) - 3kya - 4kya (Yamna culture - Wikipedia) Modern day Indians are a mix of these four groups.