Industrial Disputes (Central) Rules, 1957
14. Quorum for Boards and courts
The quorum necessary to constitute a sitting of a Board or court shall be as follows-
( i ) in the case of a Board Quorum
where the number of members is 3 2
where the number of members is 5 3
(ii) in the case of a court
where the number of members is not more than 2 1
where the number of members is more than 2 but less than 5 2
where the number of members is 5 or more 3