Bitcoin is still nor legal neither illegal in India.
Since RBI, the Head of all Banks in India, as all Banks are registered under it, so all the notifications released by it must be followed by all other Banks.
This is because RBI released a Notification which said that All the Banks and wallets registered in India (under the RBI) should withdraw their support from transactions related to Virtual Currencies or popularly known as Cryptocurrencies in 3 months of time.
After all this, some exchanges like Bitstamp still have their operations in india, do you think it is wise to trade with them? How does it work?