Collaboration amongst 3 distinct owners of floor in delhi

That must be acceptable to the bank, and the share of the borower should be mortgaged with witness signatures of other two cotenants.  One can follow the rules and regulations of the Bank and their legal counsel, as there is no other alternative.

The builder has to himself pay the mortgaged amount putstanding (as token advance) direct to the borrower's account, and builder can get those title deeds from Bank on behalf of borrower.  The borrower can issue a specific power of attorney showing the arrangements that as B has paid the outstanding loan amount on  his (Borrower) behalf, the title deeds can be handed over to him as the mortgage amount was settled by him.  The process is simple and can be done within a day.