If the the notice period is stated as 2 months and you have tendered 15 days notice then until or unless company waives off the notice pay for shortfall of 45 days in notice period, it can demand notice pay……………….and may adjust notice pay in FNF statement.
Employer can waive off notice period/pay.
If the employer does not agree to waive off it may proceed to recover.
If standing orders are applicable to the establishment then you may go thru these.
Service conditions stated in standing orders applicable to the establishment can not be negated to employee in appointment letter. If notice period in certified standing orders/model standing orders is 15days/1 month it can not be 2 months in appointment letter.
The DLC in O/o Labor Commissioner and Dept. of Labor officials can confirm if the standing orders are applicable to this establishment.
Approach your lawyer with copies of all of your docs and proceed under expert advice of your lawyer.