Yes , ofcourse  it is legal in India because I am.using bitcoin from 2 years in India , and I am proper Indian .
I have Many friends at WhatsApp group who are bitcoiner . Some of them are making lakhs per month and paying tax to the government ( which is honesty quality ) .
But in this year some restrictions comes to use bitcoin after demomentization of money which control the flow of bitcoin .
I explained about it here >>
https://bitcointalk.org/index.php?topic=1739347.new#new