Dear Sir,
It is a purely a self acquired property of your father. Yourself and your sister has no right over such property during your father’s life time. If he dies intestate then section 8 comes into role.
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Section 8 of Hindu Succession Act the wife is entitled as follows:
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General rules of succession in the case of males.―The property of a male Hindu dying intestate
shall devolve according to the provisions of this Chapter:―
(a) firstly, upon the heirs, being the relatives specified in class I of the Schedule;
CLASS I
Son; daughter; widow; mother; son of a pre-deceased son; daughter of a pre-deceased son; son of a pre-deceased daughter; daughter of a pre-deceased daughter; widow of a pre-deceased son; son of a pre-deceased son of a pre-deceased son; daughter of a pre-deceased son of a pre-deceased son; widow of a pre-deceased son of a pre-deceased son.