OP updated with more info. Surprised to know that Binance is a negative entity as per HDFC compliance list. If you want to know more regarding this communication, better ask
https://www.reddit.com/user/pradhansangam1 in his Reddit thread.
Obviously, any kind of Inward Remittance is illegal unless it is approved by RBI, RBI has set some types of remittances which are allowed as per the RBI liberalized remittance Scheme or the LRS but cryptos can never be part of it. But here once again this is an absolutely legal matter and RBI and Banks have the right to do this because this is entirely different from what the Supreme court said against the RBI ban, as that issue pertained to the usage of accounts for transactions with crypto exchanges while this issue is about getting valuable assets from abroad which comes under the jurisdiction of RBI, if Banks do this on a large scale then once again matter will reach the courts and they will decide upon it.