Gift Settlement in favour of one son ignoring the other

Hello All, I'm Arvind and I'd like to start by thanking you all for this wonderful service. Whole heartedly appreciate it. Now coming to my query; my grandfather, who has been dead for a year now, has carried out a gift settlement of our house, which is (or rather was) in his name in favour of my uncle (my father's only brother) in the year 2014 without our knowledge. In the year 2002-03, at the time of construction of the said house, a loan was taken by my grandfather (owner of the land) and my dad, together, from LIC Housing Finance Ltd. My dad was made the co-applicant as he was the only one in full-time employment (with a PSU) and also because my grandfather was retired (way back in 1990) & my uncle was self employed (and did not qualify for a loan). The loan is due to end sometime next year. My dad has paid for half of the total cost of construction of the house and is still paying the emi's for the loan along with the house tax and water & electricity bills. The municipal taxes and bills are still in my grandfathers name. My dad rightfully deserves his share in the property which is being denied to him because of this unlawful secretive Gift Registration. Please help. I'd like to thank you in advance for your valuable views and comments. Best Regards, Arvind.