Intraday 1minute or 30minute candle not providing volume info for BankNifty or Nifty50 i could see for some Options data it is coming
Indexes do not have volume data because they are not tradable assets themselves but rather represent a weighted calculation of a group of underlying securities. Since an index is a statistical measure rather than an actual instrument being bought or sold, it does not generate trading volume like individual stocks or derivatives. However, index-based products like ETFs and futures do have volume data since they are actively traded in the market.
Hope this helps. Thanks