Yes, it's applicable. Please read the applicability clause reproduced herein:
The ESI Act, 1948 Applicability
The ESI Act, 1948 is applicable to all factories and notified establishments in an implemented area employing 10 or more employees for wages.
For Factory
The threshold for coverage of a "factory," as per section 2(12) of the ESIC Act, is 10 employees located in implemented areas. At present, the Act is extended to 529 districts (as per the list available on the ESIC website at
https://www.esic.nic.in/coverage).
For Establishments
i) The Central Government has extended the coverage to the following establishments, for which it is the appropriate Government, by way of a notification under section 1(5): Shops, Hotels, Restaurants, Road Transport Establishments, Cinema including preview theaters, Newspaper Establishments, Establishments engaged in Insurance Business, Non-Banking Financial Companies, Port Trust, Airport Authorities, and Warehousing establishments.
ii) State Governments have also extended the coverage to the following establishments: Shops, Hotels, Restaurants, Cinema including preview theaters, Road Motor Transport Undertakings, Newspaper Establishments, Educational Institutions (27 States/UTs), Medical Institutions (27 States/UTs), and Municipal Corporations/Municipal bodies employing 10 or more employees.
For the purpose of registration requirements, wages drawn by the employees, whether more or less than the threshold limit of Rs. 21,000, are not relevant. Amendments issued, if any, from time to time will apply.