Gratuity

Hello,

 i need have a querry and need your support. Kindly let me know if Iam entitiled for gratity? I have resigned from  Govt . of India in the year 2008 after rendering 18 years of continous service. I was not paid gratuity. Can some one please let me know if entitled for gratuity( as i think iam) and what is the way i can claim the same now.

Thanks and regards