Convince HR For Notice Period Buyout?

Dear sir,
If I resigned from organisation and can't serve notice period then what to do.my notice period is 30 days as per appointment letter before confirmation but hr says your notice period is 90 days.
Please suggest - I don't want to serve notice period, I want to pay against notice period.

Dear Ashok,
First of all you be sure as to whether your notice period is one month or three months. If in your appointment letter, the notice period is one month, it should be hold good but if your Hr says that it is for three months, you can ask for the document or company policy where it has been laid down. Once you are confirmed about the exact duration of your notice period, you can accordingly. If you don't want to serve the company after resignation and leave early, in that case you have to pay for the notice period.
BS Kalsi,
Member since August, 2011

Payment in lieu of notice period is not a right of the employee, unless specifically provided for in the standing orders or appointment letter.
So if it is not stated in your appointment letter, then you need to sit with HR and your reporting manager and get an approval for a shorter notice period. they need to approve. its not an automatic right given to you.
Incidentally, if your appointment letter says the notice period was 1 month, then that applies, unless there is a change that was notified to you and that you have accepted, either explicitly or by not responding stating that you do not accept the revised terms of employment.