Need help on delayed flat possession

This residential project is located at Bhayandar west a 7 storay Building with 3 wings. the Landlord has agreement with Builder for development of the project, the construction work had started in 2011, had initially received permission for till 4th floor, but he was greedy and wanted permission till 7th floor but to take permission he had wasted almost 2 years. All the members and investors has already paid 95% of the money and paid for stamp duty and registration since time to time, most of the members have paid in full and most of the members are paying home loan EMIs and some are still paying Rent who have no homes. The Builder-Developer has cleared mentioned in the sale Agreement that he will grant possession by Dec'2016 but he has failed to complete the construction work, failed to withstand with any owned commitments and there are no timelines whenever we had meeting multiple times with Landlord and the Builder. the Builder is complaining that he has become bankrupt is this project, the material cost has increased, paid heavily in TDS, so he is always giving arguments that if members want possession must give the balanced money and hesitating to invest any further money into project. The landlord who has mortgaged his land is also not interested to compromise with Builder and settle down all the disputes. All the members have invested thier life savings are struggling to get possession and are been manipulated, enforced to give balance payment which is less than 5%. The Building is almost completed till the Month Mar'2020 before the lockdown, Solar, Firefighting, water harvesting painting, electricity meter, wiring, color, doors, windows work almost completed. The builder must ask the municipality is get inspection done and pass the OC and water connection but the builder is not investing any money and have no timelines to give the possession to the members. We are already in trouble and have huge financial problems, not in position to face legal court matters, we need only the possession pls help us. I have some questions. 1- Can we take move into our own flat and take the possession without the consent of the builder and without OC. 2- what are the consequences after taking the direct possession, what rights the Builder have in legal angle.