Where do I clear immigration London to Mumbai to Chennai?

Question

I'm traveling to Chennai from London Heathrow, with a transit in Mumbai. The layover time is exactly 2 hours. Where will my immigration counter be?

Answer 1

You will have to pass through immigration in Mumbai and transit domestically, since the flight to Chennai is going to be a domestic flight from Mumbai. So your passport will be checked at Mumbai.

Answer 2

On Heathrow -> Mumbai -> Chennai

You will have to clear immigration at Mumbai. Your bags usually gets checked through and you can collect in Chennai, depends on the airline. You can inquire about that in Heathrow.

On Chennai -> Mumbai -> Heathrow

Your documents will be verified in Chennai itself. You will receive two boarding passes (Chennai -> Mumbai, Mumbai -> London). When you reach Mumbai, you go through international transfer and clear emigration at Mumbai. Your bags will be checked through and you won't need to collect bags.

Exception

I once traveled on an Air India flight from Singapore, which stopped on Madurai, India and de boarded passengers traveling to Madurai and the same plane proceeded to Kochi, India. I had to clear immigration at Kochi only. But this is a very rare case.