How to legalise the gifted property to my mother.

Hello Sir Based on the agreed family partition my grandfather got 4.5 acres of his share in ancestral property. The katha of that property was in my grandfather name. My grandfather has two children my mother elder and my uncle younger. After my grandfather death in 2002 the katha was changed to my grandmother name and she was the owner of that land. My grandmother has given a share of land (1.5acre) to my mother through gift deed in 2009, my uncle has witnessed the deed and it is registered. After this that portion of 1.5acre of land katha has been changed to my mother name and she is in possession. Now when we went to get legal for that land, lawyer has said that being an ancestral property your grandmother cannot gift the land to your mother and you uncle has share in this property. Now my grandmother is no more and the remaining 3acres of land katha has been changed to my uncle name and my mother has signed as an agreement for change of katha. Kindly advise how to make my portion of land 1.5 acre a legal one. I have few options below kindly confirm which shall be legally binded one 1) Getting a confirmation deed from my uncle and his two sons (one major & minor) for that gift deed. 2) Making a partition deed b/w my mother & uncle showing our share of land and his share of land and getting it registered.