Find a bank branch by IFSC code, or a city/district/state by pincode — in a second.
Pick IFSC, type the 11-character code (e.g. HDFC0000001) and Search — you get the bank, branch, address, city, state and MICR.
Pick Pincode, enter the 6-digit PIN and Search — you get the post offices, city, district and state.
Completely free, no login.