Noc for flat resale

I am in the process of selling my flat in Pune. Below is the status 1. Builder has registered the society around 1 year back. 2. Society members are just declared and they have signed documents for handover, however kept documents with them and not submitted to society authority for handover. The reason is - there is some pending work which builder need to do. Members have communicated that once builder completes pending job, they will complete the process of society handover. 3. Occupancy certificate is already available with me. 4. I have cleared bank loan around a year back and received no claim letter from bank. 5. Buyer is taking home loan from PNB. 6. PNB is asking NOC Challenge/Problems - 1. Builder is saying since members have signed the document, members have to provide NOC. Members are saying - they are still not legally authorized since society handover is not completed. This is being happening since 15 days. Who is legally authorized to provide me NOC? 2. Now builder is asking me to pay some amount (high considering flat price), then he will provide me NOC. Do I need to pay any such amount to builder? If yes, should he provide me any receipt? Should I provide cash OR cheque? 3. Builder is saying - he can give NOC pre dated - viz before 2 Feb 16. Bank says - it will not work. Builder claims that since all members have signed document on 2 Feb 16, he cannot provide any document after that, however builder is still chairman of the society… Is builder right with this approach?