Any private agreement drafted by employer and signed with employee e.g offer letter/appointment letter/Service Rules/HR policy/Contract of employment/service agreement etc etc may not be even worth the piece of paper on which it is written.
The service conditions shall be governed by statue/Act/instrument of law/precedences set by courts of law that have become law/laws of service jurisprudence etc etc and these shall prevail upon any private agreement drafted by employer and signed with employee.
Approach many of the IT/ITeS employee's unions/Trade Unions , and able labor Law Consultant...........................and under thier expert guidance;
Inspector appointed under:
ANDHRA PRADESH SHOPS AND ESTABLISHMENTS ACT
Payment of Wages Act
and O/O labor Commissioner (state/central)
Higher officials of Dept. of Labor in your state
You will get salary slips, all documents, dues etc...............