Gratuity formula

Hello,

I am working with a software company and my last drawn Basic salary is Rs.32500/- per annum. We do not have any DA.After completeing 5 years and 8 months, I resigned and still I have to serve 2 months as notice period.

I know that the Gratuity formula as

Number of years * 15 * My last drawn basic salary / 26

What should be the number of years? 5 or 6?

Please advise me.

Thanks in advance,

Kadapa