Father refusing to give our share in ancestral property after promise

Assuming you are Hindus,

A pre-requisite condition required for a property to be Ancestral property is that it should be owned by the great grand father followed by grand father, father & present generation all in this linear generation living & enjoying the property. The property should not have ever partitioned & share in it distributed to any of the Hindu Coparceners as in any linear generation as mentioned above, in other words, it should be intact single property which is being used jointly by all members of the Hindu Joint family.

Therefore, all property inherited by a male Hindu from his father, fathers father, or fathers fathers father, is ancestral property.

The essential feature of inheritance of ancestral property according to the Mitakshara law  under Hindu Succession Act is that man inherits from any of his three immediate paternal ancestors, namely, his father, fathers father and fathers fathers father is ancestral property as regards his male issue, and his son acquires jointly with him an interest in it by birth. Their rights attach to it at the moment of their birth. 

Therefore, if your property falls within such ambit then you are  entitled for the share in his Grandfather’s property.

Hence you can file suit for partition thereby demanding your share in the land and further file an application of injunction thereby seeking order for restraining your father to sell the land.