Hostile work environment - abuse - resign under harassments

You should definitely file a complaint against the company because if you don't do this it will happen to other people too. 

 Complaint regarding Harassment against women can be made either in paper form or by sending e-mail to iccsh-dst@gov.in. 

All the facts you mentioned are a sign of harassment and work place and punishable under POSH act and under The Sexual harassment of Women at Workplace act, 2013.  You are advised to file the complaint within a period of 3 months from the last incident. 

Thanks for the reply.

But the POSH helps only women - not men. What should a man do?

The HR has been informed at a regular level about the incident, but they do not want to take any action.

What can be done if more than 3 months have passed for the incident, but HR was informed about it on the same day - with a written complaint?

"Still, my HR is not replying for more than a month and saying that due to terms and conditions" What do you mean? what reply you are expecting? 

Admittedly, you have already resigned and there is nothing to suggest that any action is pending from the Management.  As such, whatever action to be taken between the senior and you and, may be, your mother.

 

OK. What should an HR do when an official harassment complaint is filed and then the employee gives a resignation under harassment?

Should HR say that "He abused you and your mother, so it is your problem, not ours"?

There is not even such a reply.

And can HR stop the employee the details to be shared with others now? As they have taken no actions?

The situation warrants that you initiate against the former Senior.