Thank you for your response.
Eligibility for Gratuity Payment
Management does not agree to pay for that period. When I went through the gratuity act, it seems that if the principal employer is the same, then you are eligible even if you are on a contract basis. I had joined as a D.E.T., but it was also a mistake because my profile was non-technical, and I was working as a data entry operator. Later on, as I have an MBA in HR, I shifted to HR as a single person in the unit, but this was not mentioned in the documents. My joining was in March 2006, and the shift to HR was done in October-November 2006, formalized in April 2007, and from that point, I started on the company payroll.