I really don't know how they legalize or i-legalize such thing as bitcoin because you are using it with your own internet and computer hardware maybe they just not supporting it before but every citizen of India can use it no matter what happens unless their government issue a criminal liabilities in using bitcoin.
In my country Bitcoin was also banned by the government, many people thought Bitcoin wanted to be legalized in the state, but it was difficult to do so because in my country the economy was not developed and there were There are many risks involved in Bitcoin trading on the price floor