The wrong complaint to take back the property. This is the common plan

We Purchased land in 1998 from the seller. The seller was purchased this property from previous seller which was three bro. This land was purchased by one of the brother and he sell it but after my purchase of this land the third brother file complaint in 2008 that this land purchased during the common income. We all know that this was the separate family but they file complaint with the name of its brother and the put our name in complaint. This is the plan of all this three brother to take back the property. on 7/12 they was not mentioned its third brother.