Leave Rules Under the Factories Act
Your manufacturing facility will come under the Factories Act, and for that, the leave rules provided in the Factories Act will be applicable. Consequently, every employee who has worked for 240 days in the preceding year (normally, leave will be credited in January every year based on the attendance of the previous year) should be granted one day for every 20 days worked. To determine eligibility, paid holidays, leave days, layoff days, etc., should be considered, meaning only paid days, whereas for deciding the number of leaves to be credited or given to each employee, their physical presence in the factory should be the sole consideration.
Leave Rules for Trading Activity
If your trading activity is conducted in a separate premises from the factory, the employees in that office will receive leave as per the Tamil Nadu Shops and Commercial Establishments Act. Accordingly, every employee will be entitled to 12 days of EL, 12 days of SL, and 12 days of CL.
You may have more leaves, but you cannot contract it out through any clause in the appointment order.