Am i eligible for gratuity after working for 4.8 years ?

Yes you are eligible for gratuity and what you have stated about continuous serve of 5 years is correct. Your employer should offer you gratuity amount as per law without your asking but in case he does not do so you ake an application in prescribed form which is available in the Payment of Gratuity Act. You can search and download from the internet. You will become entitled to an interest from the date of application on your gratuity amount. 

What should i do if my employer says that i am not eligible for gratuity even if i have completed 4 years 8 months and 12 days in the company.

i work for a MNC IT Company.

please help. my last working day is tomorrow and i dont know how to approach.

Thank you for the help.

Expert Mr.Thukral has appropriately advised.

The employer is under obligation to supply the Notice of Determination of Gratuity and Payment within 30days from LWD or interest @10% pa is applicable.

You can also submit FormI and write (under proper acknowledgment ) that Notice of Determination of Gratuity and Payment of Gratuity has not been supplied despite representations in office and be supplied thru Redg. Post.

Let employer write back whatever it wants.

If you are unable to handle to resolve on your own then you may entrust to your able counsel.