What is this establishment: Commercial or Industrial?
You are located in which state and Redg. office of the company is in which state?
The notice period may be mentioned in advertisement calling job applications, offer letter, appointment letter, service conditions stated in standing orders applicable to the company…………………………Shops and Commercial Establishments Act of the state……
The service conditions stated in standing orders can not be negated to employee in appointment letter…………………….thus if notice period is 30 days in standing orders it can not be 90 days in appointment letter.
You may show the appointment letter issued to you, standing orders (Certified/Model), Shops and Commercial Establishments Act of the state to your lawyer……………………and the lawyer that has seen all of your docs can advise you the best.
Is it stated in appointment letter that employee shall complete the projects in hand?
Even if it is stated since notice period is 30 days the exit formalities including knowledge transfer etc has to be completed by company in 30 days……………………….
You may affirm in notice of resignation initiated by you or in subsequent communications (covering all communications/representations made by you till date and mention dates………….names/designation/dept of company’s officials to whom you have represented with brief minutes of discussion) that notice period stated by you is 30 days as per clause number……………….in appointment letter dated………………issued to you, and last day in office/effective date of resignation is dated………………..and within this period company should ensure that all exit formalities, handing over of charge, company property, knowledge transfer is completed…………
The company should inform you in writing the formalities, formats/forms etc and who has been designated as replacement and to whom you should handover charge………….
You may affirm that you are willing and shall co operate and are available for handover, knowledge transfer within and up to last date in office…………………dated………………..and routine should be assigned to you that can be completed within and up to dated…………………….
Even if as per some internal policy of the company your boss has to decide the date of relieving it can not be beyond the period of 30 days that is the period decided as per bilateral agreement signed by company with you.