Company is not relieving me early even though i'm ready to buyout

Dear Sir/Madam : Below if the clause in my contract. I was given very low rating and company was planning to put me in PIP ( performance improvement plan ), and eventually terminate me ( that's what most companies do ). This is all due to organizational politics. Everyone knows i'm good performer. I scored highest marks in all technical exams. Now i found another job, the moment i came to know they were planning to put me in PIP. Now when i'm asking HR, and my manager to relieve me early, all of sudden to my surprise i've become the most in-demand resource. They want me badly. They say there is resource scarcity in the project. They are not even showing any progress to find my replacement. I've clearly told the HR in an email about mental harassment in my project, still no action. I also told them that i'm ready to buy-out notice period ( i.e pay the money for remaining notice period ) but they won't listen. Now I'm planning to go to labor court/office. But i need your advice if this is advisable. Below is what my contract says regarding notice period. Kindly suggest what should i do ? I shall be highly thankful to you. """""You will be required to give 60 days’ notice to terminate this appointment. The last working day would be decided at the sole discretion of the Management and in the event of being relieved within the above number of days, the remaining part of notice period days would be adjusted against the existing leave balance or an equivalent of Basic and HRA components of salary. The Company, however will have the right to terminate your appointment forthwith on account of misconduct, including but not limited to, fraudulent, dishonest or undisciplined conduct, or breach of integrity, or embezzlement, or misappropriation or misuse or causing damage to the Company’s or Client’s property or breach of the confidentiality obligations. In all other cases, the Company will have the right to terminate the services by giving 60 days’ notice or payment of Basic and HRA components of salary in lieu of notice."""""