Dear Gautam-Das,
You will get mixed answer to you. Many learned members will say that you are eligible for but I will say that you are not eligible, seeing you are from Delhi from your profile.
My advise to you is under this circumstances, not to spend your time knowing the answer from such forum and make your claim for gratuity with your employer. If your employer deny then approach the controlling authority. If the controlling authority also deny then approach the court.
You make a request every where as stated above to apply the analogy of judgements by HC at judicature Chennai and Kerala.