Beats
Possession not given Even if Full Payment made

I have booked one flat in last year feb. and builder told me for possession in dec. Builder has completed work in feb and i have made full payment in the month of feb-11, even Stamp duty price also paid. After that builder is saying that he is in problem of income tax due to raid, so not did Dastawage. and then Jantri comes in picture to hold. Now builder is asking for Interest to do the Dastawage.

Please suggest what I can do...

Waiting for help!!