Can we transfer money to Zerodha a/c from any bank other than registered bank a/c through IMPS/NEFT?

Can we transfer money to Zerodha from any bank a/c other than registered bank a/c with Zerodha through IMPS/NEFT? My present registered bank with Zerodha charge small amount for IMPS/NEFT whereas from another bank account its free but its not registered with Zerodha.

Yes, you can. but first, you need to add the other bank as a secondary bank account.