Tax on inherited property

My grand father wrote a property division document according to which the house property will devolve from him after his death to his wife and then to my father after my grandmother's death.After my father's death me and my mother got legal heir certificate according to which property now devolves on me and my mother.

My question is

1.whether the property division document can be considered as a will.

2.Any capital gains is payable on several transfers stated above.