Dear Tito,
Payment of Gratuity Act is applicable to-
(a) every factory, mine, oilfield, plantation, port and railway company;
(b) every shop or establishment within the meaning of any law for the time being in force in relation to shops and establishments in a State, in which ten or more persons are employed, or were employed, on any day of the preceding twelve months;
(c) such other establishments or class of establishments, in which ten or more employees are employed, or were employed, on any day of the preceding twelve months, as the Central Government may, by notification, specify in this behalf.
A shop or establishment to which this Act has become applicable shall continue to be governed by this Act, notwithstanding that the number of persons employed therein at any time after it has become so applicable falls below ten.]
Hence, every such establishment has to mandatorily pay the amount to the eligible employees on separation after completion of eligible service. In case of default, the employee can approach the Controlling Authority as defined under the Act.
Regards