1) In India are you free to become whatever you want and that is granted by the constitution?
How about drug smuggler, tax evasionist, organ trader?
I'm fairly sure there's a clause with an exception for illegal activities. Should this be the case, then their central bank's specific ban of cryptocurrency, which isn't illegal, has no legal grounds.
I've yet to hear that a court order can make an activity legal, if the principle of separation of powers in a democratic country really work as they supposed to, only the Parliament would be able to change it, not a court.
The thing is, it's technically not illegal. There's no law that states banks can't deal with cryptocurrencies. It's apparently just a circular from their central bank, which could be scrutinized and found unconstitutional by the courts. If nothing else, this is democracy's checks and balances system working.