What to do if there is a dispute regarding the ownership of the land

I have a house in Bihar, in front of my house there is a land (called bhinda which belongs to Bihar Govt.), then come main road and then come pond. I used to go main road through a land (called bhinda). Now some people of my village made boundary around the land (called bhinda), therefore I am not able to go main road through the land (called bhinda). When I asked them, they said this land ( called bhinda) belongs to them, their grandparents did bandobast of this land ( called bhinda) when there was jamindari system exist in Bihar. Please help me how to overcome from this problem??