Shri. Varghese Mathew is very correct. I wish to add value to his reply. The ESI Act applies to any premises or precincts where 10 (20 in three states) or more persons are employed. The appropriate government—state or central—is empowered to extend the provisions of the Act to various classes of establishments, whether industrial, commercial, agricultural, or otherwise in nature.
Under these enabling provisions, most state governments have extended the Act to certain specific classes of establishments, such as medical and educational institutes, shops, hotels, restaurants, cinemas, preview theatres, motor transport units, newspapers, and advertising establishments. Additionally, the Allahabad High Court held that the word "otherwise" is of wide amplitude, covering all other establishments, including educational institutions. Medical and educational institutions established and run by Ramkrishna Math and Ramkrishna Mission are excluded from ESI coverage.
Regards.