Flats
Re Registration and completion of the flats

I have purchased 2 flats from a promoter as per agreemnt in the month of August. The promoter has not delivered the flats completed in all respect even after expiry of the one year time in spite of the fact all payments except the 10% amount that is to be paid at the time registry, has been paid. We are in all 12 flat owners and only 3 flat owners agreement are yet to be registered. We all the flat owners wish to form a co operative and rgister it so that we can force the promoter to abide by the agreements. Please suggest.