Surrender of flat booked under subvention scheme

I have booked a flat at noida expressway with a builder under subvention scheme i.e no interest payment till possession. He has got Rs.53 Lakh loan on behalf of my wife and son. Now due to some family disputes it is looking difficult to take the flat or continue with the deal. I would request you if I drop that deal writing builder and bank what would be the legal consequences we have to face or they will accept our plea and close our file. Regards