You have initiated the termination by notice of resignation and since you have not served full notice period you have caused a breach and have to compensate by tendering notice pay.
The notice pay/compensation @ Basic, Gross, CTC should have been clearly stated in exit clause of the appointment letter, standing orders of the company.
If it is not defined then it should be Basic pay.
The notice pay/compensation should be same for employee and employer: equitable discretion.
Therefore you may go thru the appointment letter, standing orders carefully.
In ID Act a mention of Notice is made that an employer is to give to employee in case of Closure of the establishment, Retrenchment, discharge…………..and in such case payment in lieu of notice is Basic + DA………..
Other version is since employer disburses OT, paid leave, Bonus, Gratuity @ Basic + DA, retrenchment compensation,………….. therefore notice pay may also be calculated @ Basic + DA.
Lay off/retrenchment compensation is stated in standing orders, appointment letter………therefore these may be referred to check on rate of notice pay also.
And that pay means Basic pay (fixed part of the pay), DA…………….
You may check if paid leave is encahsed in FNF statement/settlement it is calculated at what rate.
One more point is that employer (good offices of appointing authority, MD, Chairman, Company Secretary……..HR/Line management is not employer and they are other employees in the company) can waive off the notice pay.
Therefore if you can peruse and convince notice pay may be waived off.
Another point is that as per IESO Act 146 Rule 13/Model Standing Orders the probationer, temporary workman is not entitled to notice, hence no notice period and notice pay is applicable.
If your establishment is covered under Shops and establishments Act of the state then you may go thru the Act. For some states notice period for service below ……………….. months is NIL.( e.g. Delhi below 3 months)
-----------The amounts mentioned in the CTC are contractual obligation on the company.
If bills are not submitted your company may disburse but may ad the amounts in taxable component, and you may not get the IT relief.
If the manager to whom you have submitted the bills has not forwarded to HO then you may need to produce some witness, evidence that bills were submitted.
The manager may forward the details how your bills were forwarded to HO.
You may look at alternatives to obtain certified copy of the bills from the sources which issued the original bills.
If you can you may try and record the transaction ( visual) during which the manager admits that you had submitted the bills to him.
Usually in companies some excel sheets are created each transaction.
You and your manager may rely on these.
If the manager admits bills were received and forwarded then you are not at fault.
You may submit a carefully structured representation to good offices and proceed as deemed fit at your end.