With Builder NOC can we get ownership of that property

We stay in chawl from last 45 years. 4 years back owner died. so his grandson got all property.(chawl + empty land) He sold this property to builder without tenant NOC and started construction. We filed case against them , judge gave 5 years stay on construction. Judge prove us the legal tenant as well. Now new builder bought this property. He wants to start construction. So he offers us 1. He will give flats in his scheme but we have to bear construction cost. OR 2. He will build home for individual in chawl. Now original owner sold the land to builder which was 21 guntha. so builder has approved plan of 21 gunthas. But the actually land is more than 21 guntha,. So builder is offering us , he will build 500 sq. meters houses on excess land for us and will provide NOC for it. I have few questions. 1. If we accept first option, we will be owner of flat clearly but if we go with the second option who will be the owner of that house. 2. Builder will give NOC, but can we sell this house in future with help of NOC.