Originally Posted by oliver2002

If you have a visa you should be fine, no one will question your activities. Online checkin for international flights is not possible in India so all you will get is a confirmation and you have to collect a physical boarding pass. When you deplane in BOM you will be led to the immigration counters. Don't follow the crowds, but be on the look out for the Intl transfer desk, which looks like this:





The agents there will try to get in touch with your next airline and print a boarding pass for you. 90 min for the entire process should be OK, (it took me 54 mins last week to go thru immigration, collect my bags and check in with AI for a domestic flight at 1am) but I would plan for a bit more, you never know.