You’d have to get the coin bags from a bank branch for which you must have an account. That said, most branches do not offer these services anymore even to their clients. Generally you must have a business account for this.
similarly, to get banknotes, you must be a client. This is easier than getting coin bags, but no guarantee they will be unc notes
you could go to the RBI and in the main hall there are a couple of coin vending machines. You can put bank notes and get coins in return. However I didn’t use them in years and from what I remember, the lines became longer and they limited upto Rs100. I think at some point they prevented people from coming altogether unless you could verifiably show that it was for your business
you can try going to a coin dealer and buying them, but they will charge you a premium. Usually 2-3 times face value or more depending on what you want.
the final option is to go to a shop and ask if they will give you some coins. In Bombay , I don’t think the coin shortage situation is particularly bad, But shops might not be willing to part with their change
you can go to the Mint store at the bombay mint which is across the street from the RBI in South Bombay. Previously they had a token system, but I’m not sure that’s the case anymore. They have proof and unc sets as well as some coin cards. unc and proof sets are in the 3500-4500Rs range, coin cards are around 300-400rs range
the RBI has a money museum which is well worth a visit. I haven’t been there in years, but when it had opened i was very impressed
keep in mind that india stopped issuing commemorative circulation coins since 2015 except for the 75th independence anniversary set . You might find older commemorative coins in change. The new Rs20 coin should also be freely available
