Illigal Kabza with Threat

Respected Sir, I Mukesh Kumar, living in Delhi. and belong from Madhubani, Bihar. the Story is there are 40 Bihga Agriculture Land in the Name of my Fathers of Grand Father. My Grand Father was Two Brother. as per law what i have knowledge Total Property will be Devided in Two Parts, my Grand Father has One Some , My Father. and Other Opposite Party have 6 Son. now the younger son of Opposite Party has illigal kabza on my land . we have documents. but they fight with us with their sons. and threat us . we complain in panchayat also but they support him. now the younger son of Opposite Party has beed expired. yesterday i call him for divide the property as per documents they are denying and saying that go and call to my father. i will no in favor of devide. this time i am sing only 20% of total land. i request you to please advice me where i have to complain about this. how it can be settle all they are doing criminal activities. is it possible we can apeal my case in delhi. Need Reply.