I want to revert the changes made by a specific admin user in Drupal 6.37. In all the pages that I want to revert, the create new revision box was not selected. Hence, I have no way of finding out the changes.
If you don't have revisions you can't rollback the changes unless you have a database backups that you can use to restore and old copy of your site.
Back up and restore your Drupal MySQL database, code, and files or migrate a site between environments. Backup and Migrate supports gzip, bzip and zip compression as well as automatic scheduled backups.