Grandson Rights on Grand father self acquired Property.

Hi, I would like to know the procedure and related Documents required to claim the Mutation of my grand fathers property to grand children's (my Name and sister )from my dad name. Our's Hindu family. Below are my queries::: 1. My Dad's not very responsible person like other dad's. He's completely addicted to Alcohol, Race and other stuffs. Even though he's a Govt Employee he didn't earn or saved anything in his life and no personal savings as well.Now he And all his 4 other co-brothers are willing to sell a piece of my grandfathers self acquired property.with regards to this as a grandson would like to know is there any rights for a grandson to stop selling the property of my dad's share which is of 10000 sqft( green land). All his co-brothers are not supporting to me. How can I stop and get that land Mutated on me and my sister name, as we don't want to sell at the moment. Incase if I have a rights what all the documents required to file a case. Appreciate if someone could help me on this. Looking forward to hear from you.