Builder NOC for Loan Disbursement

I am selling my flat which is 10 years old. The Buyer is taking loan from Axis Bank. All verification and documentation has been completed. The Bank has asked to complete the sale deed and registration and post that they want me to get NOC from the Builder (as society has not been formed) and submit for disbursement of cheque. I told them that I will provide NOC from Builder and only then the sale deed and registration to be done as I would want all documentation clear before doing the sale deed and registration. I dont want to take the risk of having the property registered in buyer name and then get NOC as later if there is issue in getting NOC from builder as per Banks requirement I would have already transferred to property to buyer and would have to run around for the cheque disbursement. The Bank person is insisting that NOC from Builder is to be taken only after registration as the registration number should also be mentioned in the Builder NOC format. Please advice is this the process with all bank follows and is the bank right in asking for NOC to be taken after registration. Also is there any alternative to meet the Bank requirement Regards