I did the international to domestic connection with different PNRs at BOM a few days ago. My Turkish flight landed at 4:45am and I had a connection departing at 7:30am. The immigration area was a complete zoo. The lines went all the way back to the escalators. Very few counters were open. It took me more than an hour to go through immigration. Luckily I had no checked bags and made comfortably to the next flight. But many people in the line missed their connections.

I will not try this again without at least a 4 hour layover. Unnecessarily stressful.