Partition of property by panchayat can we challenge the partition

Partition between dad and his three brothers for there parental property which has property of my grandfather and his brothers through there mother's(my grandmother) will is taking place. Partition was decided through panchayat which had friends of my uncles and some neighbors. There are some points on which my grandmother doesn't agree. Like eldest son getting the house alone, built by him using parental resources like bricks. She wants to give half of the house to my dad and his youger brother. She is not happy with the eldest two. Can she create a new will to counter this will later on?