Related to farming land

I have one query, please help me in that my grandfather was 3 brother 1. My grandfather's elder brother (died) - he was having 4 sons means my uncles (my 3 uncle died and 1 is alive) 2. My grandfather (died) - he was having 2 sons, my father and my real uncle (my real uncle also expired) 3. My grandfather's younger brother (missing) - he had left the home around 45-47 years ago and at that time he was not married, and we don't have any information about him, that he is alive or not, he got married after that or not. so, now we want to distribute the land of my 3rd grandfather land,so I want to know how will it distribute, 1) will it divide as per brothers basis in 2 parts (grandfather's elder brother and my grandfather),? 2) or it will divide on nephew basis means in 6 parts ( 4 sons of grandfather's elder brother + 2 sons of my grandfather's)? 3) or what happend if my uncle and father expired after completing there full, in that case how the land will divide. JFYI, I am from UP (uttar pradesh), so how land will distribute here?