Purchase of Flat which is ready for development agreement signing

Hi, I have purchased a flat from one of the seller of a building which is undergoing the development agreement. All the exciting tenants have signed the development agreement but for 7. My seller is also a part of the 7 who are yet to sign the development agreement. The development Agreement is already presented for registration at the registrar's office with my sellers name. He is being invited to sign the same document which is already been sign and executed by others. The current stage of the document is admission pending since 7 clients are yet to sign and execute the DA at the registrar's office. My seller is not signing it since he has sold the flat to me. Now my name does not feature in the DA which has the sellers name and has been presented for registration at the registrar's office. I want to know whether the builder can incorporate my name in the DA? Or even if the seller signs the DA, can the Permeant alternate accomodation agreement be signed by me. Since the develop