(1) Where there are numerous persons as parties to any proceeding before a Board, Court, Labour Court or Tribunal or an Arbitrator and such persons are members of any trade union or association, the service of notice on the Secretary, or where there is no Secretary, on the principal officer of trade union or association shall be deemed to be service on such persons:
Provided that where personal service on the Secretary of the Principal Officer is not practicable the service of the notice may affected by affixing a copy of the notice on the outer door or any other conspicuous part of the office of the trade union or the association.
(2) Where there are numerous persons as parties to any proceeding before a Board, Court, Labour Court or Tribunal or an Arbitrator and such persons are not members of any trade union or association, the Board, Court, Labour Court, Tribunal or Arbitrator, as the case may be, shall, where personal service is not practicable, cause the service of any notice to be made by affixing the same at or near the main entrance of the establishment concerned.
A notice exhibited as mentioned in sub-rule (2) shall also be considered as sufficient in the case of such workman as cannot be ascertained and found.
21. Procedure at the first sitting. -- At the first sitting of a Board, Court, Labour Court, or Tribunal the Chairman or the Presiding Officer, as the case may be, shall call upon the parties in such order as he may think fit to state their case.