Illegal termination

I had been working in IT company for 15 months from oct 2015 to march 2017. I had received performance appraisal in dec 2015 and company was happy with my performance, sincerity and commitment. But to my shocking on march 31st march 2017 my manager called me and told since you require promotion and you are not happy in present company you have to leave company from today.Company HR told they will pay three months salary.This was verbal communication. As per appointment letter it is mention the company may terminate your services without assigning any reason with three months notice in writing with a compensation equivalent to your one months salary. My three months salary credited on apr 28. I have filed petition in labour commissioner office in month of june for illegal termination for company did not not gave me three months notice. In fact I have received performance appraisal in month of december 2016 where it is mention company is happy with my performance. In reconciliation meeting company's legal hr claiming since i have accepted three months salary I do not have right to claim for reinstatement and they have terminated me for misconduct. I am single earning member of family I was busy finding job getting job was prority.But i could not find job till 20 th of june so i filed petition against company on june 28th. I am claiming for reinstatement but company management is not ready for it. Do I have right to claim How should I proceed further. How much amount I can claim for illegal termination .Please guide me further?