Land dispute on ancestral agricultural land.

Hello Sir, My father has 3 siblings- 2 brothers and a sister. My grandfather passed away in 1998(at an age of 92). My grandfather had kept his ancestral agricultural land (7/12) papers on names of his 3 sons only. Later, after his death, my aunt got her name on this agricultural 7/12 land papers. My aunt has also passed away in the year 2005-06 Later when my father and 1 uncle were misguided by talathi to add names of late aunt's sons and daughters (to 7/12 paper) and got their signatures on it. Also my late aunt's sons and daughters are married, possess their father's agricultural land and are financially well off. (Location: Maharashtra) My query is - 1. Whether just having names on 7/12 papers makes you eligible for property(agricultural land) ownership? 2. Since my grandfather and his daughter also passed way before 2005, Can my aunt's sons(and daughters) claim for land ownership? 3. Please suggest some way forward to get this issue resolved. So that agricultural lands can be divded amongst my father and 2 uncles.