Dispute over land

Hi Sir/madam, My parents had bought a piece of land few yrs back. My Maternal Cousin brother had requested to start a small term business in the land without any legal transfer of the land, so with verbal decision,he made a farm house for farming business. At that time my father was not aware of the fact that he is turning out to betray us by claiming that that land is his because he has made a house there and he has stayed in that land for more than 5 yrs. Basically all the legal documents are in for of my father, and that particular land is not registered with my cousin brother name yet. Now he is trying to pull my parents to the court by building up illegal documents which claims that he has made an agreement with my father and by doing false signatures and few neighbourers signature that this land has been given to him and they are the evidence. Now my parents are afraid that for legal civil case lot of money will be wasted and the case will be dragged for many years. My cousin brother is rich so he could afford the same, but my parents are not that rich to afford that much salary to a advocate.So can they fight their case of their own? After listing to the case do you feel, my parents would win the case because we have all the real documents and proofs that land is ours and that guys has only build an house over there. Please let me know in my email id - [deleted], if you could help me with this case.