Conditions for a Hindu marriage are stated under section 5 of the Hindu Marriage Act, 1955, which says, “A marriage may be solemnized between any two Hindus, if the following conditions are fulfilled, namely:
(iv) the parties are not within the degrees of prohibited relationship unless the custom or usage governing each of them permits of a marriage between the two;
(v) the parties are not sapindas of each other, unless the custom or usage governing each of them permits of a marriage between the two.”
Section 11 of the Hindu Marriage Act, 1955, says that, “Any marriage solemnised after the commencement of this Act shall be null and void and may, on a petition presented by either party thereto against the other party, be so declared by a decree of nullity if it contravenes any one of the conditions specified in clauses (i) , (iv) and (v) of section 5.” Therefore according to Hindu law, a marriage between persons belonging to the same gotra is absolutely null and void
But Delhi Court emphasized that there is no legal prohibition regarding marriages taking place within same gotra (ancestral lineage) and said it is the court’s duty to ensure that such couples who marry within the similar gotra are not harassed by their parents or police.
You can also register the marriage according to the Special Marriage Act, 1956. If both of you are adults, then your parents cannot legally restrict you from marrying a particular person.