Hi @Jadhav, Jyoti ,
Welcome to Q&A forum!
Do you mean to migrate the files in Windows Server 2008 to SharePoint Online? If so, SharePoint Online, as a cloud storage collaboration product, is not picky about the file version. So there is no compatibility issue that you are worried about. And you can refer to this article for migration: https://learn.microsoft.com/en-us/sharepointmigration/fileshare-to-odsp-migration-guide
If I understand it wrongly, please provide more details so that we can get on the right track to solve the problem. Thank you.
Good day!
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.