Total possessed area is 466 yards but as per registry/sale deed total area is 300 yards and registered will by grand father of his part

My grandfather and his brother was living since 1957 at a place in Haryana total possession was 466 Yards divided equally between my grand father and his brother but total area is 300 Yards as per Registry. In the year 2012 he has made a registered will of 233 Yards of his part of property between three of his sons i.e. 100 yard in the part of his first son, 100 yard in the part of his second son and 33 yard in the name of his third son. We have passed map of property of total 466 yards in local municipal office and paying house tax since the year 1957. But now dispute between three of sons. Two sons are agree as per registered will and third one has possession in 33 yard as well as 100 yard. He is not vacating both the parts by saying that my grandfather had no right to do registered will as this area is out of registry. We are running suit for injection in court to remove his possession from 33 yards as we have already leave the possession from 100 yards given to him.