I agree with the requirement your management has. Go ahead and put it very clearly in the appointment letter: in case you do not complete your notice period, you will not be entitled to a relieving letter or experience certificate. In addition, we will initiate legal proceedings against you for the recovery of the notice pay and any direct losses caused by your failure to complete the notice period.
If the situation actually arises, go ahead and deny the relieving letter and experience certificate. But make it very clear to the management that if the employee goes to the labor commissioner or the court (very few will actually do that), we may be forced to provide the experience certificate. However, this is applicable only for the shop and establishment, not the factory, and if required by the state laws. Also, note that what you need to provide is a service record, not an actual experience certificate. As I have mentioned before, read your standing orders and the shop act in your state.