Dear Mr. Abhijitmahato,
You are very well applicable for Gratuity. According to the Gratuity Act 1972, you are eligible to get the gratutiy after the completion of Five years. It is calculated as 1 year if a person completes 6 months of service therefore apart from the 2 years of your tenure you have completed 4 years & 240 days a year is deemed to be complete in terms of continuous service. Your 2 years of contract will also be added even if you were in contract, but should be in continuos service without a gap.