Google simply does not allow to change ownership of files from external domains, as you are not the owner of the Google Drive files, you cannot perform an action such as taking ownership.
You cannot change the externally owned file and transfer the ownership to a user from your domain.
However, GAT+ allows an Admin to copy the Externally owned Folder and its content and place it into User’s drive from your domain.
Open GAT+ navigate to Drive audit.
Find the files you want to copy using the Custom filter.
Use any of the Custom filter options to find the External owner
As an example search Folder by title ‘Marketing folder 2020’. You can use any other search option to find the folders you need.
When the Folder by the external owner is displayed
Owner of the folder will be with orange background – meaning external user
Click on the arrow beside the name (Marketing folder 2020) a list of options will be displayed.
Select Copy this folder
A new window will be displayed you can check the detailed info.
Click Next to proceed
A new window will be displayed.
Select the user where you want to add the Copied folder into.
Advanced mode – will give option to set up and add Destination Parent Folder ID
When you select the user, a drop-down list of the recipient Drive Folders will be displayed.
Pick and choose the folder where the Copied folder will be copied into.
Click on Send request for Security officer approval
The Security officer will receive an email with the request to be approved.
From the email, the Security Officer will be navigated to Copy management
Under Actions select approve or deny action.
Check the progress of the request in the Admin log or the eye icon under Copy management
When the request has finished, the Folder with its content will be copied over to the selected user of your domain.
The original owner Folder – below
The copied folder will be located in the selected location while copying.
Note: When copy is completed, the comments added in the original documents will be deleted, but the content of the files themselves will be the same
For additional information please contact us at email@example.com with any questions you might have.