We are migrating to SharePoint Online and we want to check that which all sites are using variations in SharePoint 2013. Is it correct that if a site contains variation labels then that site is using variations or is there any other criteria? Please let me know if there is any powershell script to check that.
Yes, if a site contains variation labels, that site is using variations.
I am afraid there is no PowerShell script to check if the site is using variations.