Regarding getting land back from developer

Sir,

My father have had purchase plot from a developer way back in 1985.

Thereafter the land was aquired by CIDCO and NO communication was done to my father in this regard.

However, we found that the CIDCO has alloted land to the developer.

The developer is now not co-operating for allocating land to us back.

We do have the original sales deed with us.

Can any one help me in understanding as what should done to get the land back?

Thanks and warm regards

DEEPAK