I have no idea what is involved in getting fish to India, but what you need are species that live in tropical tide pools. I doubt that many/any suitable species are comonely collected for the aquarium trade, but your best bet would be to talk to a collector and ask him to go to a tide pool at a low tide at noon and catch what ever fish he finds still living in the pools.
This July, I was exploring some tide pools in the Florida Keys, and I was amazed by how hot the water was. I did not measure the temperature, but I would be very surprised if it was below
40C. It burnt my feed as I walked though them. And the pools were not lifeless, they were quite a few fish swimming around apparently quite content with the water temperature.
I have no idea if the
larvae could have withstood that temperature though....