How to transfer ancestral property when grand uncles are refusing?

My grandpa has property in Uttar Pradesh.but he migrated with his family in Maharashtra 30 years ago. The property is of my great grandfather and the land was equally divided among his four brothers ( among them my grandpa is eldest). Two years ago he gave power of attorney to one of his brother. Now he died two months ago. We have only zerox copy of power of attorney and no property paper.we even don't know how much land is in our grandpa name.we have death certificate,caste certificate.my grandpa brothers are not giving the correct information of land and nor they are eager to do property transfer work.is it possible to take land on my father and his 3 siblings (2 sis and 1 bro) without going in UP(via online)?. My grandma is alive.please someone solve my problem. Thank u