Mental harassment

I am a mother of 1 year old child. When I joined the company as test engineer when my baby was 5 months old. Me and my husband are in same organisation. For 3 weeks me n my husband worked under same manager. Due to some personal reasons this manager did not like us. Then I was shifted to other project under different manager. Again this manager gave negative feedback about me to my new manager. After a week only My new manager said that my performance is not good and after that discussion nothing happened. And suddenly when probation period got over then said that your performance is not good and we need your replacement and at this time only one month was left for the project to get over. There was no issue miss nor any escalation was raised. I escalated the same to the head HR and after that they put me under PIP(PERFORMANCE IS OBSERVED). I requested them that if you want to check my performance then please assign me under some other project as this manager is already influenced by other manger's feedback but they didn't agreed and again put me under same project. After a week the head of this company came to India for some visit. I told him the complete matter and requested him to change my project. He agreed and sent me the confirmation mail for the same. But after 2 weeks nothing happened and they fired me out of the company. Now i want to file a case against them. So can I do that in this scenario?