Forced resignation without giving any reason to favor friend of CFO

I was working as a VP of a reputed company for 1.5 years.I am highly qualified with Engineering and MBA degrees, certifications, have very good credentials from CEO of earlier organizations, highly respected by colleagues, have 30 years professional experience in Banks, NBFC,IT companies. Unfortunately, all of a sudden, I was called by HR head and advised to resign within 3 months and threatened that if I did not, I will be terminated. He did not give any reason. I found out from other sources that this was done to accommodate a close friend of CFO who has formed a coterie of vested interests around MD. I am 57 and have not been able to find a suitable job because upper age limit for most senior executives is 55. I have left the company about 11 months ago. I have two daughters, one in USA and another in school to support. Me and my family is on street with no pension.Firms resort to emp contract as defence.How can I claim for damage to finance ,dignity against unethical,inhuman acts?