How to enforce partition of land in joint family

Religion - Sikh Caste - Jatt-Sikh In Punjab, there is agricultural land against my mother's name. My mother has only one brother.Till now they are using that agricultural land. Now when me and my mother asked them to release that land, they refused to do so. In FARD(document having land record) 1/3rd of total land is registered against my mother's name.But Taqseem (partition) is not done yet i.e killa numbers are not registered against my mother's name. So my mother hold 1/3rd share of total land. But which land or killa number out of total are not yet registered. It is difficult to takeover(kabza) of our share as they are not releasing and ready to fight. Someone told us to put an application for taqseem (partition) of land so that killa/land numbers should be registered against my mother's name. And after that we can easily sold that land to someone. Please help me out to move in right direction. What is right for us ? What steps should we take so that we should get our land.