The challenge is to have an ATL India that while still partitioned as in OTL, becomes an independent state as a sovereign, nationalist (instead of socialist), secular (or non-secular) and democratic republic.
Inevitably that likely entails butterflying away Mahatma Gandhi and Jawaharlal Nehru though as yet do not know enough about this period to see which right-leaning leaders / figureheads would be suitable alternatives within the Indian Independence Movement.
How would a Nationalist India without the political dominance of the Nehru-Gandhi family compare to the OTL India?
And what-if a Nationalist India despite the challenges manages to end up being comparably developed or even more economically developed country (GDP, etc) then OTL China by the present day?