Resignation and notice period

Hello, Situation: I'm working in an IT consultancy company in Bangalore and I have resigned with a notice period of 1 month whereas my work contract specifies a notice period of 2 months by either party. I'm not willing to give 2 months of notice period but I'm ready to pay the shortfall of notice period (say, 1 month). On the other side, my employer is threatening me that they won't give me any relieving letter if I leave early. Here's an excerpt from my employement contract: Notice For Termination: The written notice required for termination of employement will be 2 months notice by either party. You would be required to serve the stipulated notice peiod and early release would be at the sole discretion of the management. In case you leave your employement without giving requisite notice, no relieving letter wil be issued and settlement of dues will be at the sole discretion of the management.However, under CSC India's disciplinary procedure your services can be terminated without any notice period. Question: A very simple question, I want to get relieving letter from my employer and I'm ready to pay the price for it. What does law in India stipulates ? Does employer really have the power to hold relieving letter and form 16 ? What can be done ? Thanks & Regards pdhawan101@gmail.com