Work Place Harassment and Retaliation after complaint to HR.

Dear Sir/ Madam, I has been working in IT MNC (Name can't be disclosed due to company policy) Programmer Analyst Trainee, (Employement details not disclosed due to conpany policy) and deployed in Unitech, Kolkata Location since 12 months. I was harassed and badly treated by my colleagues and Supervisor for more than 4 months. I made complaint with my Manager (Name). 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. I asked for relocation to Pune, Gurgaon, Bangalore, Hyderabad. So that, I may be in safe side from my career and my mental health prospective. I had produced a depression medical certificate too. As a retaliation, They have hold my confirmation and have given worst rating/feedback with baseless and silly comments which seems to be as allegation. Now, This is extreme harassment by Employer. I had written an email to almost all senior most authorities including CEO of the company. But at all no action has been taken and I am forced to work here only in Kolkata within same account and with same people. They had given transfer to many resources like me but they are not giving transfer to me. They made me in Depression and high blood pressure. I did't have any option other than lodging complaint with Labour Ministry. Central Labour Ministry official has informed me that he has forwarded my case to Labour Department in Kolkata. Refrence of Complaint: ...... Please assist me as soon as possible that what type of legal action I can take against employer.