Forefathers land partition among 2 brothers then their childrens

Hi Dear Law experts.. I'm looking for your inputs to proceed further actions. Background: My grandfather's father(GFF) had 2 sons and 1 daughter. My grandfather(GF2) is Younger for his father. Land(24+12acres) was registered on his brother(GF1). GF2 went to his sister family to help them after her death. He spent nearly 20years there, while he was there he brought 5 acres land & sold it, returned to native place. When he reached native place his brother sold 12 acres of land without his consent. And his brother is not willing to give share in the land. After villager's involvement they had agreed for give 9.5 acres instead of 12 but this is only for farming and not ready for transferring land. After 15 ywars, in 1999 his brother was realized and agreed for registering land onto my grandfather(GF2). In 1999 land has been partiotioned to have 12 acres each. In 2000 and 2002 both grandfathers were passed away. My grandfather had 2 sons and that land transferred onto his 2 sons in the year 2008 with 6 acres for each. In the year 2009 other grandfather sons went to Revenue Divisional Officer's court to cancel 2008 registration. Since years case is running. Over couple of months back Tahasildar(MRO) reported as 14.5, 9.5 acres of land is using by both the parties and both parties were not agreed for solution, so Tahasildar suggested to reach out Civil Court. What could be RDO judgement in this case? Can he cancel earlier registration? There is no wil written by both grandfathers, can RDO make partition with inequality i.e. 14.5 vs 9.5 instead of 12 vs 12? Allegation: As my grandfather brought and sold 5 acres land so they want 2.5 acres compensation from our 12 acre land. Does it really stand in court? As he brought on his own money and sold out due to his personal issues. Looking forward for your inputs on it. Thanks a lot in advance