As per the provisions of the Payment of Gratuity Act, 1972 and according to the your circumstances-
1- In the first and third phase of your job you have not completed the minimum time for gratuity. The minimum time for elegibilty is 5 years of continous service.
2- Only in the second phase you are completing 5 years of service. You can entitled to get gratutity only for this second time frame i.e. for the purpose of calculating gratuity, your length of service will be only 5 years.
3- According to Section 4 of the Act Gratuity shall be payable to an employee on the termination of his employment after he has rendered continuous service for not less than five years,--
(a) on his superannuation, or
(b) on his retirement or resignation, or
(c) on his death or disablement due to accident or disease:
4- Your employer is very correct if he is asking for your written regisnation for payment of gratuity.
Pankaj Singh Rana,
Assistant Labour Commissioner, UP