Family Property issues

My grandfather died in the year 2009, and left with 5 sons and 4 daughters. He also left with properties with his name and my grandmother’s name. My father was the eldest son of my grandfather. My grandfather suggested to my father to stay separately in another house due to family issues. We have not separated with anything legally, my father stayed in another house to avoid any family issue from the year 1995. In the Year 1997, my uncles (Father’s brothers) created a WILL mentioning that all my grandfather properties will go to only four sons excluding my father. That WILL is registered. However, my grandfather looking to our family conditions gave my father a non-registered WILL in the year 2008 and in that he mentioned all his properties will go to my Father only and will not go to my 4 uncles. In the year 2011, my father passed away and now my uncles based on their WILL selling the properties and giving my grandfather properties to my father’s sisters. They are also asking my mother’s signature and on behalf of that giving one very less valued property. Can we claim the grandfather properties based on the WILL my father got from our grandfather. The WILL is written by a legal document writer on a plain paper and signed by my grandfather. Also can we (grandsons) claim grandmother’s properties? Please advice.