Kindly follow the advice of Mr. Kameswarao, Mr. Madhusudan.
Pay means basic pay, personal pay if any, officiating pay, if any and DA. Therefore notice pay as mentioned in offer is calculated on Basic + DA.
Is your designation/position covered under ID Act.
Same is taken for Gratuity calculation, Retrenchment pay, compensation, PF, Leave encashment etc. Therefore, the notice pay on the part of employees shall also mean the same, i.e. Basic + DA.. Does your company provide leave encashment on basic+ HRA+ Spl. All. If yes what is wrong in applying the same for notice pay?
However to be specific it is advisable to refer to the Standing Orders of the company.
You may also read 13. Termination of Employment in Industrial Employment (Standing Orders) Central Rules, 1946.
In private sectors definition of pay may be different. So recovery in lieu of notice pay may be different. In some case it is the fixed part of the salary Basic +HRA.
Dearness allowance (D.A.) is part of a person's salary. D.A. is calculated as a percent of the basic salary.You can also refer to the concerned personnel in HR who shall guide you to company policy on DA and DA component in your salary. O/o Labor Commissioner can guide you to applicability of DA as per your designation/class of employee and class of industry you are employed in.
First company decides particular employee's basic pay then refers to Minimum Wages Act and find percentage of DA for particular category of employee's & then calculate Basic + DA. To find the DA for companies that are covered in Shops and Establishment Act one may refer to notification of Minimum Wages Act applicable to the state.
You may go thru the letter amending the notice period signed and accepted by you. It might be mentioned that notice of resignation or notice pay @ ............basic or gross pay. Or it may be mentioned other terms and conditions as mentioned in appointment letter shall remain the same.
Was it mentioned that if change is not accepted, employee may tender resignation? In all probabilities company shall not mention it in this letter. Company may send email/circular and use language which may be a concealed threat to accept or leave. Do you have any such email/circular? If such transactions are verbal by line management/HR employee should be smart enough to record (audio/visual) and use it at appropriate time in appropriate forum. Although employee would like attain stability during employment in a company, however employee should always be exploring better options. If during tenure employee has been a performer a company would like to rehire such employee.
Even under situation as mentioned by you employee should remain amiable and keep the rapport and goodwill and apply persuasion, persistence, negotiation, reasoning skills. Good offices of appointing authority, MD can waive off the notice pay and your line management/HR can help you by recommendation and follow up. There is nothing wrong in attempting. If persuasion does not work, you have the option of adopting legal approach.
Vlauable advice of learned experts/members is sought.