As per the RBI directive, bank account holders need to necessarily provide their PAN or Form 60 to the banks. PAN is a highly important proof of identity which is used by banks to authenticate transactions of financial nature with the person concerned. In case you do not have PAN, you are required to submit Form 60 together with supporting documents such as address and identity proof with the bank to undertake banking transactions.
Further to this, in its December 2016 circular, RBI disallowed debit transactions in all such accounts where PAN or Form 60 has not been furnished by the account holder. Further, for the banks to debit freeze your account, following two criteria are looked upon. First if in case an individual's bank balance is Rs. 5 lakh or more and second in case the amount deposited after scrapping of high value Rs. 500 and Rs. 1000 notes is over Rs. 2 lakhs.
So, in case your bank freezes your bank account in respect of debit transactions no amount can be withdrawn from it neither any debit transaction even electronically can be done from it.
Hence to unfreeze your debit freeze bank account you need to provide the bank with PAN or Form 60 at the earliest. For it you can either visit the nearest bank branch, send an e-mail to the designated customer services dept or do it through the online mode. In the online route, the banks in general have an Update PAN link when you log in your account using net banking. There you can key in your PAN details and upload self attested copy of PAN or Form 60 supported with requisite proof copies. Banks after verification of the documents will unfreeze your bank account.