With a POD no earlier than the start of the Second World War (edit: and without dramatically changing the outcome of the war... I wanted to write this as end of the war, but frankly that's too late to change the politics much) get a single, sovereign and democratic Indian state. Bonus points for the closer the date of independence gets to historical, and for reduced violence and increased stability.
Basically how could independence have been better managed (with a definite focus on avoiding partition)?