1, unite with the owners you bought in the same batch and find the developer to handle the property certificate together. I believe that there is an agreement in your contract about the handling of property right certificate, and insist that the developer implement it according to the contract;
2. If the developer does not reply or delay, complain to the local real estate management department;
3. Entrust a lawyer to handle legal procedures.
If the developer really goes bankrupt, it is necessary to write to the government together with the owner to let the government know about it. I believe that after bankruptcy, the government will handle the aftermath.
Does the Housing Authority have any records that can be found?