Dear @Ankita,
Thank you for posting your question in the Microsoft Q&A forum.
May I ask a few details to better support you:
Is this file a meeting recording that was automatically saved in the channel, or a video you stored elsewhere and later uploaded to SharePoint? Have you opened this file before? If yes, did it play normally at that time, or did you already see the same issue? Or was it working normally before and only recently started showing this problem?
This information will help me identify the cause and suggest the right next steps.
Looking forward to your response!