I think the obsession on these forums with splitting India is weird. Splitting China would make a lot more sense; Tibet and Xinjiang/East Turkestan are to this day distinct nations, and due to 20th century conflicts and the Dalai Lama, Tibet is a well known entity, more so than any previous Indian states. China is also a far larger video game market, so adding extra Chinese Civs like Manhuria would seem to be far more viable than adding extra Indian Civs. Splitting India would not make sense commercially I would imagine; it may be a big country, but it's video game industry is very small considering that due to poverty.
I'd be
so down with Tibetan, Uyghur, and Jurchen/Manchu civilizations (plus a few historical Tocharian city states), but that would
never fly in China - the PRoC and RoC governments don't event recognize
each other, they (especially the former) would not accept the notion that those regions could ever be independent from China.
Also, China has a long history of being a single state. The idea of "India" as a monolithic entity is a very recent phenomenon and a largely Western idea. Splitting India just makes more sense from a cultural and historical perspective.
If I were to split India, I would do it like this:
India - specifically representing North India/the empires of the Indo-Gangetic plain. It would have multiple leaders, representing the Mauryan, Mughal, and Maratha Empires (so basically Ashoka, Akbar, and Shivaji), and possibly also the modern Republic (so Nehru as a DLC leader, though we would probably get Gandhi

). Focused on Faith and a "wide" playstyle.
Tamils - Representing the Chola/Pandyan dynasties. Focused on culture and maritime trade/naval combat.
Karnataka - Representing the Deccan states - the Hoysala/Vijayanagara Empires, maybe third leader representing Mysore or Hyderabad. Focused on culture and city-state interactions.
Punjab - Representing the Sikh Empire - focused on Faith and War.
And MAYBE...
Bengal
Nepal
Kushans - Though these guys could easily be counted as a Civ distinct from India.
City states would fill important gaps like Kerala, Odisha, Gujarat, Lanka, etc.