Thank you for reaching out to Atlassian Community!
When it comes to migrating users from one organization to another, it's possible to do that only by transferring the products.
When transferring products from a different Cloud domain to an existing organization, you will be able to manage all the users in one place, but in this case, you will have to remove the domain from Organization A and verify it on Organization B.
For more details, please check the documentation below:
This question was tagged as Cloud, that's why I added this information. Sorry for the misunderstanding.
Atlassian access is not available for Server, so the steps and documentation I mentioned don’t apply to Server.
Can you please let us know more details about what you meant by Organization? I'm asking because in Server there are Customer Organization and not Users Organization.
Do you need to migrate users from one instance to another?
Thank you for the details, @Amit Anand.
In case users are on an internal directory, then to move them to a new instance, it will be necessary to create a backup and migrate the entire instance to a new one.
If users are on an external directory such as LDAP or Crowd, then you can connect the directory to the new instance.
For more details, please refer to the documentation below: