Brother selling ancestral property

We have some agricultural land in a village in Tripura. It was my grandfather's property who passed away a long time back. The land was held jointly in the name of his two sons: my father and my uncle. No partition had been done. A couple of years back my uncle sold half of the property to another person. However, the value of the land which he sold, as his share, exceeds the value of the remaining land by a lot.

My father, a few days back, got my uncle's name cancelled against the remaining land and now the remaining land is in his name only. Please suggest me what I can do to get an equitable share, not just by area of land but also by the value. The person to whom my uncle had sold half of the property has already sold some part of the land to a third party. Can anything be done now or is it too late?