Full OC and Handover of New building

We bought a flat in a society which is re-developed. But now the new tenants came to know that the builder is not supportive to new flat buyers. He is meeting with old committee members who are old members before redevelopment for full OC and Handover process but not entertainning the new members at all. Old committee members say that we are yet not members and we have NO SAY in handover. There are still pending works to be completed by builder but he is in hurry to apply for full OC and Handover to old committee members. My question is Is old committee have powers to act as committee even after redevelopment is over but before full OC is pending. What are rights of new tenants with whom builder is not responding - construction quality is pathetic and builder is not responding, old committee is not interested at all to solve issues of new tenants bcz they say we are not yet members. Can builder apply for FULL OC and give handover to old committee without any permissn from new tenants. What are rights of new tenants here before handover if builder is not completing the work to the satifaction of new tenants as promised at time of sale.