Mahima,
Others have already told you want to do on the issue of the offer letter
However, there is another aspect.
No one is allowed to shout at or abuse in an office.
You need to take this up with your management and get them to instruct others in the office (your male collegues) or the security to either stop this person from entering the office on grounds of abusive behaviour, or to intervien and remove him from the office in case of unacceptable behaviour.
I don't know how badly he behaved, but if the abuse was of a personal nature or if you feel he considers you as the reason for removal and therefore constitutes a threat outside office, you may ask your manager / director to help you report the matter to the nearest police station.
Others have already told you want to do on the issue of the offer letter
However, there is another aspect.
No one is allowed to shout at or abuse in an office.
You need to take this up with your management and get them to instruct others in the office (your male collegues) or the security to either stop this person from entering the office on grounds of abusive behaviour, or to intervien and remove him from the office in case of unacceptable behaviour.
I don't know how badly he behaved, but if the abuse was of a personal nature or if you feel he considers you as the reason for removal and therefore constitutes a threat outside office, you may ask your manager / director to help you report the matter to the nearest police station.