Property partition

Dear Sir/Madam. My Father and My Elder Father are the owner of land, constructed building 50% share each, My Father died 10 years ago and my elder father and their two sons are taking all rent from the flats constructed without giving us single Pie, the two sons of my elder father are not earning but only taking rent and maintaining their family. I and my younger brother and my family are suffering with their sarcastic behavior and keeping all the land, household and rent in their possession since my father is also 50% share of the property, we are staying as joint family, we have one 1100 sgft field near to our house and when I asked them that I will constuct one two bedroom flat, they said no and create all sort untowards incident to stop me constructing the house. I want to ask if my father and we two sons are the 50% shareholder of the property then what are the possible ways to construct my house and get 50% share as I need my house to be constructed within one year. we are from Cuttack, Orissa