1) There is no way that the company can force you to serve the full notice period.
2) The clause in the employment agreement usually states "ninety days’ written notice or three (3) months’ gross salary in lieu thereof". Therefore if you are willing to pay the company should not raise any objections.
3) Put in your resignation serving your preferable days of notice and be prepared to return all the company properties or assets that are in your case and custody at the end of this period.
4) If the company refuses to accept your resignation in person/writing send it to the company via email at the same time. The company should be ready to adjust the leave against the notice period if you have earned leaves accumulated.
5) Where there is rule there is a punishment for the breach of the law, you can breach the contract by paying the damages to the management. However, the management has no right to retain even after payment of the damages as per the agreement. Thereafter, you should issue a written notice to the management by communicating about further development and requesting your relieving letter.
6) If the new employer has no problems with your not getting a relieving letter or experience letter then you may just join the new employer after the required days of notice in the current company. The company can not act against you in law.
7) If your employer intentionally dragging your case to issue relieving letter than you can approach the labour court or the tribunal by issuing lawyer notice to the Management, HR and Reporting Manager.
8) In the extreme case you may also consider moving the High Court under Article 226 read with Article 14.