REGARDING RESIGNATION - Hr In Company

HI
As per my company rule notice period should be 3 months ok
I have resigned with 15 days notice period ok
my hr says that you have to pay gross salary for 75 days
so my query is that should i pay gross or basic of salary if basic then suggest in which act this provision exist.
please suggest.

What is written in your appointment order regarding notice?
That will be binding.

AS PER OFFER LETER,
1> EITHER PARTY MAY GIVE 3 MONTH NOTICE PERIOD IN WRITING OR THREE MONTHS SALARY IN LIEU OF NOTICE TO EFFECT THE TERMINATION.

3 Months salary means it is 3 months gross salary which is paid monthly. It is not Basic Salary. It is clearly mentioned in the Apptt.Order & it is binding. There are no Act / Laws made separately for it.
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