In 1991,there was a registered partition deed between My grandma,my dad, 2 of my dad's brothers and my dad's sisters..(In all 5 partitions). In the partition document she had stated she has no rights in childrens property after that. However in 2002, MY dad passed away, because of which My grandma had become a part of my dad's Legal Heir certificate. My dad's Legal Heirs are myself, my brother, My mom and Grandmom. In 2013 one of my uncle tricked my grandma and wrote her 1/4 part in my dad property to his name through a SETTLEMENT DEED. My self and my grandma have asking the uncle to write back the 1/4 of the share which he to wrote to give it back,but he is not responding in a way that he is going to give it back.
My dad's property is 5 acres of agricultural land, because of which I am not able to sell the property/nor do some business on that property.
Can my Grandma cancel the Settlement deed she wrote in 2013 now, if so how it can be done.