Account Number, Account details, Bank Account
Please provide the account number where you want the tax refund to be credited. This is the main account and incase of inconsistency the refund issuance will fail.
IFSC
You can get the IFSC code from Cheque book or passbook. Generally the first four digits of your account number is similar to your IFSC code.
Bank details, Other accounts
Please provide the details of all the bank accounts you held during the concerned year, including the account you hold jointly. You can leave the accounts which are lying dormant for more than 3 years.