According to succession laws, a Hindu male's father is not an immediate legal heir. Here's a look at who are considered legal heirs of a Hindu male who dies intestate.
When a Hindu male dies intestate (i.e., without a will), his assets will be transferred to the immediate legal heirs. In the case of a married Hindu male, the assets (such as property, mutual funds, bank accounts etc.) will be given to his widow, his children, and other immediate legal heirs in such manner as provided in the Hindu Succession
the class 1 legal heir of the Hindu male if he dies intestate and will inherit the ancestral as well as the self-acquired property of the Hindu male. However, the Hindu male could disinherit them from the self-acquired property by drawing a will to this effect. They will still be legal heirs to inherit their share from the ancestral property.