In the case of serious misconducts, the company can withhold the reliving letter. Normally, when an employee completes the required notice period he will be relieved and letter issued. But when there is a disciplinary action, the relieving will become a formality only, and it will be against the pending enquiry. In your case also, since you were found to have involved in an offence, dereliction of duty, your relieving letter can be put on hold till the enquiry is on. However, the bank management dismissed you without conducting an enquiry. That can be challenged. Suppose the bank had issued a relieving letter, and in the letter it is mentioned that you have been dismissed, what value the letter will add to your career? Therefore, the relieving letter has no significance so long as the termination is challenged, and it is proved that you were innocent. Then they will have to change the status from ' dismissed ' to resigned.
Since the matter has been referred to the Labour Court, you will have to wait. If you were not given opportunities to prove your innocence other than a show cause notice, the court will remand it back to the labour officer and director him to see whether procedures required to be followed before an employee is terminated is followed or not, and during the course, the bank may settle the issue by changing the status. Wait for that