Hi,
Just because some employers include the term Gratuity in the CTC does not change anything as far as the applicability of the Payment of Gratuity Act. It will and shall remain the same with 5 years being the criteria in employment continuously, subject, however, to the technical qualification of the last year if anyone resigns, retires, or superannuates in the fifth year, in which case 240 working days come into play.
Thanks and Regards