If government launches a "crypto currency" it will be tied to the FIAT. So we will no more able to call it as virtual or crypto currency but it will be more like "digital money". Or in other words, its going to be similar to PayTM or other PPI wallets. With players like Jio have PPI licenses and government has spend large amounts to establish IMPS infrastructure based on which UPI runs, I think, India already has the FASTEST digital money system and also the fastest cheque clearance system. So, if RBI launching a crypto currency means, something that is built on top of say Ripple or Stellar Lumen, it will be just another waste of tax payer money. The existing IMPS network itself is not used properly and IMHO there is no use of RBI launching any virtual/crypto/blockchain based payment system.
That being said, I am quite sure that they will launch something like virtual/crypto/blockchain as its going to be completely useless and our number one priority is to do wrong things in the fastest way. So I believe and expect more waste of tax payer money just like Aadhar project.