Related to validity of the will

My father had bought a land in an auction ,,,,,later on he had expired and the property was divided between me, my brother and my mother around 2004 through an unregistered deed(VIBHAJANA PATRA as called in kannada),,,my mother had 5 children: 2 sons and 3 daughters,,,, Now, my mother had Willed all her properties in the name of her daughter's and she is expired now,,, Do we(sons) have rights,,,, If yes how??? Whether it is a self acquired property of my mother or not??