property issue: how to issue duplicate paper of property

sir i have 2 querry 1) almost 20 yrs before my father and uncle bought the land in patna and paper was with my uncle. my father still don't know the name written on the property paper. is there any way to issue the duplicate document of the property....? 2) if the owner is my father then in that case can his brothers claim on elder brother property, however all younger brother is well settled...??