Study your appointment letter/terms of appointment carefully. Obtain the opinion from your lawyer.
You may fix up an appointment with your reporting authority and HR and using persistence, patience,negotiation skills, common sense, good conduct,convince them with your view point and offer to help them find a replacement /handover charge/help to complete assignments and tell them that you shall be available and accessible for help whenever required.You should perferably minute the meeting.
Resoloution thru discussion is the best wayout.
If you feel that desp[ite offering best of the cooperation the employer is unwilling, you have to take the lagal recourse.
The experts have pointed out maximum you shall have to remit notice pay.
The employer pushes since reference check by consultant/employer is a practice and the emplyeee would need relieving letter/NOC NDC/form16/work expereience certificate/PF transfer -withdrawl etc, and many of the employees do not keep themselves updated on their rights and legal traps and wayouts.
It is better to retain a good lawyer and seek legal advice in case of a doubt and avoid a situation.
Seek opinion from your family and experienced well wishers before you sign on dotted line.
Try and build rapport in this and future ventures, to ensure smooth transition for you.Be smart.