VGP — Vgp arjun town

We own a 1200 sft plot in Vgp arjun town purchased in 1996 which is now understood to be under a court case.
Recently we were approached by a third party informing that an ex Mun Councillor is ready to buy the plot at 8 to 10 lacs which is hardly 20% of present market value. We were also informed that this is the only best opportunity available to get some returns from the plot. There are many plot owners in similar state with regards to this plot.
We feel it is a scam or illegal proposition.
Can your organisation help us in getting a fair market value for the plot.