Society NOC for selling a 40 year old property going for red

I live in Mumbai in a society which is more than 40 years old (1972). The society has been approaching many builders since 2007 and finally has appointed one in 2012 we had signed an MOU valid for 1 year in October 2012 . However the issue is the buildings property card was not clear and hence there is more delay in this process. I intend to sell my flat and I am getting buyers. However when the buyers are going for a loan, despite the fact there is no MOU valid now and no redevelopment agreement, the society has asked me to take an undertaking from the bank in a 100 rupee stamp paper that the building is in process of redevelopment and we are fully aware of it. Is there a way out of this. If so, please guide next proceedings.