Bank asking to get court order or succession certificate for locker

First, you should ask the bank to furnish a copy of the notice that they are referring to. If a succession certificate or a letters of administration is absolutely necessary then you may be required to approach the courts to have one issued. You may also inquire into who your father had appointed as a nominee to the account if he was eligible to do so. If you were the primary holder of the account then there should be no reason why the bank would prevent you from operating the account. File a written complaint with the manager of the bank and have it sent by speed post. Further, you may also write a complaint to the RBI and while a RTI application inquiring about the procedure to be followed in such a case. Feel free to get in touch if we could be of any further assistance to you.