It is good that you have feel of nuances of the matter. Employee should be properly informed. A properly informed employee can defend his interest much better.
You are in which state and Redg. Office of the establishment is in which state?
How many employees are employed in it?
What was the date on appointment letter (Actual Date of appointment or it was willfully backdated) and did you affix actual date of receipt by you below your signatures?
If it was backdated and if you received it in date (50 days after date of appointment) you may create noise! Although you had the opportunity to decline to accept this clause alone in writing and could write declinature on the original copy issued to you with carbon impression on your copy. The service conditions inserted in appointment letter drafted by employer or communicated subsequently are negotiable and employee has full right to reject or accept or ask to negotiate! As in a contract till accepted in writing the conditions may not be deemed as accepted and have become enforceable.
Otherwise also T&C that violate law/statues are void to that extent.
The employees, employee’s representatives, employees unions, trade unions can negotiate service conditions. Trade Unions are willing to embrace employees from al sectors.
Designation alone does not decide a worker shall be covered as ‘Workman’ as in ID Act, as ‘Employee’ as in Shops and Commercial Establishments Ac or not! Your lawyer can opine you are covered or not!
There is a provision of ‘Work’s Committee’ and it is an authority. The president of the committee is on rotation from employees and employer.
Read; The Industrial Disputes Act, 1947
CHAPTER II: AUTHORITIES UNDER THIS ACT
3. Works Committee