Builder in Nerul
Gave possesion of flat already registered on others name

I have being given possesion of flat which was already registered on others names. I have already paid full amount and have registered agreement & possesion letter. Other person has already registered same flat around four year before me and has lodge complaint that I alogn with builder cheated him.

I have already paid huge amount of money for flat and now am affaraid of loosing flat.

Please help