What do you think would had happen had Japan conquered India in WW2?

The Japanese planned to run India through their Indian proxies in the Indian National Army, so I doubt they would be so heavy handed. It would be more like the Vichy/Imperial Japan situation in Vietnam or Thailand during the war rather than Manila or Nangking. I think the Japanese actually really respected Bose and believed in the INA movement, which is why they may? have helped him escape after the war. My own speculation is that Bose made it to the Soviet Union and they planned to use him to undermine the Raj but then became redundant to the Soviets after India was granted independance.