The Hindu Marriage Act, 1955 is not applicable to:

Section 2(1) of the Hindu Marriage Act, 1955 applies the Act to followers of the Brahmo Samaj, to Sikhs, and to any person who is a convert to the Hindu religion. Section 2(2) provides that nothing in the Act applies to "the members of any Scheduled Tribe" within the meaning of Article 366(25) of the Constitution, unless the Central Government directs otherwise by notification.