Gratuity is a part of salary that is received by an employee from his/her employer in gratitude for the services offered by the employee in the company. Gratuity is a defined benefit plan and is one of the many retirement benefits offered by the employer to the employee upon leaving his job.
An employee may leave his job for various reasons, such as - retirement/superannuation, for a better job elsewhere, on being retrenched or by way of voluntary retirement.
So it is clear that to receive Gratuity there must be employer employee relation.