first regulations regarding eligibility
1. Gratuity is given if he have served for continuous 5 years..in 4th year it should be more than 240 days.
2. In case of death or permanent disablement?? then the 5 yrs count is invalid.
3. now for calculation of gratuity you need to know his/her Basic+DA
CTC figure wouldnt help in calculating graatuity in your case.
4. Its calculated on the basis of 15 days per completed year of service...
5. Its divided by 26, as in gratuity calculation we take 26 working days for a month., not 30.
6. the formula:-
basic+da * 15 * number of service years / 26
for more elaboration on gratuity norms follow any legal book....