Dear Chander S.Sharma,
"workman" means any person (including an apprentice) employed in any industry to do any manual, unskilled, skilled, technical, operational, clerical or supervisory work for hire or reward, whether the terms of employment be express or implied, and for the purposes of any proceeding under this Act in relation to an industrial dispute, includes any such person who has been dismissed, discharged or retrenched in connection with, or as a consequence of, 9 that dispute, or whose dismissal, dischasrge or retrenchment has led to that dispute, but does not include any such person--
(i) who is subject to the Air Force Act, 1950 (45 of 1950), or the Army Act, 1950 (46 of 1950), or the Navy Act, 1957 (62 of 1957); or
(ii) who is employed in the police service or as an officer or other employee of a prison; or
(iii) who is employed mainly in a managerial or administrative capacity; or
(iv) who, being employed in a supervisory capacity, draws wages exceeding ten thousand rupees per mensem or exercises, either by the nature of the duties attached to the office or by reason of the powers vested in him, functions mainly of a managerial nature.
So, if the Gross Salary of those supervisor is below Ten Thousands rupees, then they will covered under Workman category and thus you have to include them under CLA Act.
Hope this will help you.