The map given during gift deed is wrong.

My grandfather father gifted 60 cents of land to my mother through gift deed in 1999.We converted 10 cents land for residential purpose in2000.Map show we have road access.Again in 2014 we surveyed the land,map shows us road access.Both my grandfather and my mother no more.We filed suit for our mothers share in grandfather property and won the case.Court commissioner allotted land adjucent to 60 cents .Map drawn accordingly.Now we came to know that we don't have access to 60 cents land.what todo