Employee
Section 2(9) of ESI Act

Any person employed for wages in or in connection with work of a factory or establishment to which the Act applies.

In order to qualify to be an employee, under ESI Act, a person should belong to any of the categories:

• Those who are directly employed for wages by the Principal Employer within the premises or outside in connection with work of the factory or establishment.
• Those employed for wages by or through an immediate employer in the premises of the factory or establishment in connection with the work thereof.
• Those employed for wages by or through an immediate employer in connection with the factory or establishment outside the premises of such factory or establishment under the supervision and control of the Principal Employer or his agent.
• Employees whose services are temporarily lent or let on hire to the Principal Employer by an immediate employer under a contract of service (employees of Security Contractors, Labour Contractors, House keeping contractors etc., come under this category).
• Employees employed directly by the Principal Employer in any part, department, branch situated in the same station or else where, in connection with administration of the factory or establishment for purchase of raw materials, sale or distribution of the products of the factory etc.

Exclusions are 

• An apprentice engaged under the Apprentice Act, 1961 or under the Standing Orders of Establishment. 
• Any members of Navy, Army or Air Force and 
• Any person whose wages (excluding overtime wages) exceed Rs.7,500/- a month.