The author of the thread has clearly mentioned that they are in the manufacturing industry, meaning they are covered by the definition of the Factories Act and will fall under Schedule II clause (ii). I would like to elaborate on this below:
Definition of Employees Under the Factories Act
The following persons are considered employees within the meaning of section 2(i)(dd) and subject to the provisions of that section. This includes any person who is:
(ii) Employed in any premises where a manufacturing process, as defined in clause (k) of section 2 of the Factories Act, 1948 (63 of 1948), is being carried out, or in any work incidental to or connected with any such manufacturing process or with the article made, whether or not employment in any such work is within such premises or precincts, and where steam, water, or other mechanical or electrical power is used.
Now, please carefully read both clauses. It is clear that the definition is ANY PERSON WHO IS EMPLOYED. The word "Employed" has been used in both clauses, which means any person employed. Are managers/supervisors, etc., not employed?
Earlier, the definition used to be "Workman" under 2(n) (old Act).
So, my point is, as far as the employment category covered under Schedule II is concerned, all employees are covered irrespective of their designation.