Make it so that in the division of India, there is enough Buddhist population in the Raj to warrant the creation of a Buddhist majority state alongside Pakistan and India. What is a likely name for this state, and what regions would it include?
Mass conversions of Dalits would help in terms of absolute numbers. There actually has been a movement that has been doing this for some decades, now. Have this happen earlier -- say 18th or 19th C and in greater numbers. I have no idea what region might be most conducive for this or how to concentrate converts into a state, though. Migration to one of the historical holy centers in India, perhaps. Creative gerrymandering by the British as part of an independence settlement? Cue communal riots, though.
Another thought: covert a ruler of one of the princely States to provide the necessary foci.
Burma? Wasn't it part of the British Raj IOTL?
That actually started in the 19th century; the real problem with this route is that while they are mass conversions, they're still a very small amount of the population, and it's occuring in the Heart of Hindudom.
How would this new state reconcile having an army with their pacifism / abstain from violence?
How would this new state reconcile having an army with their pacifism / abstain from violence?
How would this new state reconcile having an army with their pacifism / abstain from violence?
Easy, just include Sir Lanka in the Raj.
If you mean on the mainland then your best bet is in the North-East; IOTL Buddhists make-up large minorities (in the 30-40% range) in Arunachal Pradesh and Sikkhim and are the second largest religion in Mizoram (though only in the 5-9.9% range); outside of Assam, which is majority Hindu (though only in the 60% range) most of North-East population went through religious changes in the 19th and 20th centuries, with large scale conversion to Protestant Christianity, so perhaps have some Buddhist movement/leader go to the area that becomes popular and proselytizes and have the North-East become majority Buddhist, leading to a movement for separation from the rest of India.
Mass conversions to Buddhism by dalits did occur on many occasions. But they were not on a scale that could make a decisive change in the demography. The total population of Buddhists in India is less than 2% while the population of Hindus is above 80%. Hence a Buddhist Indian state was not plausible at the time of independence.
Actually there was such a Buddhist state partitioned off India. It was partitioned off India in 1937, ten years before independence and final division. That state was Burma and now called Myanmar. And yes, until 1937, Myanmar was part of British India.