If a man marries a girl who is within his prohibited relationship and his custom does not permit such…

A marriage within the prohibited degrees of relationship, not permitted by custom, contravenes section 5(iv) of the Hindu Marriage Act, and the punishment for contravening clauses (iv) and (v) of section 5 is prescribed by "Section 18(b) of the Hindu Marriage Act 1955", namely simple imprisonment up to one month, or fine up to one thousand rupees, or both.