Trainee employee went to court to file a case against us as well as the police station. How do we tackle this issue as an HR?

Without prior communication, the employer failed to issue a relieving letter. Consequently, the trainee employee was terminated. Subsequently, the employee proceeded to file a case against us and also visited the police station. How should we address this issue from an HR perspective?

Please provide the full details and the background. How do you expect someone to advise you on such little information?