Farmlands possessed by relative
Firstly you should file for temporary injunction under order 39 of Civil procedure code. Then, if you had given the farmland to your uncle for supervision and all and then he has taken possession of the property then you can file a case under section 406 of Indian penal code that talks about punishment for criminal breach of trust.
Or if he is staying there without your permission then you can file a case under section 448 of Indian penal code, taking about house/ property trespass. Also a case of wrongful gain can be levied. Also he can be charged for criminal trespass under section 447 of Indian penal code, that talks about a person having lawfully entered into any property, unlawfully remains there with intent thereby to intimidate, insult or annoy any such person, or with intent to commit an offence.