Section 15(2) in The Payment Of Gratuity (Central) Rules, 1972
(2)Where there are numerous persons as parties to any proceeding before the controlling authority and such persons are members of any trade union or association or are represented by an authorised person, the service of notice on the Secretary, or where there is no Secretary, on the principal officer of the trade union or association, or on the authorised person shall be deemed to be service on such persons.
