Buying Notice Period

Hi,
I am working with an MNC.I have submitted my papers for my resignation and currently on notice period. However my offer letter says that the Notice Period is of 2 months. There is no clause of pay in lieu of notice period. I'm willing to serve the notice period of one month.
Now the HR is insisting on to pay the amount for one month remaining.. and that too Gross salary amount for a month.
As far is I know. the in lieu amount should be of Basic.
Does the labour law states anything related to this.
Please Help
Thanks
Sajeesh

In the absence if clause in service agreement "to pay salary in lieu of service of notice period", you can do so. Claim made by HR to pay salary for the remaining one-month notice period is correct. Normally in the agreement only Gross salary would be referred to. Hence it OK but not to include the reimbursements.