Harassment by Employer, what legal actions can be taken?

Dear Sir/ Madam, I am working in IT MNC. I was harassed and badly treated by my colleagues and Supervisor for more than 4 months. I made complaint with my Manager. He did nothing on this and then I reached to Senior Manager, then to Associate Director, Senior Director and so on. All of the business leads including HR department started harassing me more and more. As a result of my complaint of harassment, I became soft target. They had threatened me to hold my confirmation and worst rating. I reported the same to HR too and also to all senior most authorities in Cognizant. But they did it. Please advice me about appropriate legal and police help. I have already made a complaint to labour commissioner. Thanks