Mumbai, Mumbai...
Once we weren't able to get any reply from Mumbai on this route... Luckily cruising at FL430, and we just contacted Male Approach by ourselves...
Muscat ACC is easy, as the transfer from UAE ACC. Read the Jeppesen enroute charts, no big deal.
Take some extra fuel (single runway, can be busy). I had to hold once.
Advice: At first contact with Male, ask if any delay to be expected, than reduce speed if necessary.
Enjoy!