Ansal Escencia Sector 67

We have a beleaguered property (booked in 2011) that has been handed over to us by Ansal on ‘as is where is ‘ basis. Partly completed but No registration or OC. As part of the agreement we cannot seek legal recourse. They gave us some compensation. As we were tired of their constant procrastination and unreliability we have taken possession and are now planning to finish the rest of the paperwork and internal work. The building has 3 owners in all. Can anyone advise what should we prioritise next . TIA