Upvote:1
Careful with the tickets! Mumbai has different airports. If you have to change terminals or change airports then you will definitely need a transit visa.
In fact, changing airports would be a big hassle. Double check on your ticket.
Upvote:3
As stated in Timatic, the database used by airlines:
TWOV (Transit Without Visa): Holders of confirmed onward tickets for a max. transit time of 24 hours.
TWOV normally means not clearing immigration, including in India - thus you cannot TWOV if having baggage to pick up (which, with separate bookings, you have to).
Furthermore, even if you only have hand luggage, at most airports check-in staff requires the trip to be in a single booking in order to board you on the basis of TWOV. This is in part because if something happens to your connection, you're not "insured" for the rest of your trip and the airline that took you to Mumbai may have to send you back if you can't pay to have the connection re-booked.
So yes, you will need a transit visa