heard about Daman as a place but not sure if electricity charges are really cheap might be the case. And Kashmir actually never heard about free electricity across India or low electricity cost as such. Good if your friend is mining for free with no electricity. Also is there 24 hours electricity @ Kashmir?
Daman is the cheapest place to mine if you live in/near Western India, and if you are from North, Kashmire is the best place.
I do know a person who mines there for free with no electricity charges there, but don't know about 24 hours electricity as it is a terrorist-oriented place where many attacks take place all of a sudden.