Upgrading to 6.0.0.0 is only supported from 5.3.6.0 or later. If you are running a version older than 5.3.6.0, you must first upgrade to 5.3.6.0 or later before upgrading to 6.0.0.0. For customers running on a release earlier than 6.0.0.0 and needing to upgrade to 6.0.0.0 or higher, please contact Delphix support to help coordinate this upgrade.
If you are upgrading from a version < 6.0.0.0 before you begin the upgrade process, contact Delphix Support to perform some pre-checks.
The procedure for uploading an upgrade version to the Delphix Engine is:
Login to the Delphix Setup application.
In the Software Version panel, click View.
Click the plus icon to upload a new version.
Select the upgrade version you downloaded from the download site.
The upload begins on the drop or selection of a file (upgrade image) into the Upload Upgrade Image window. You will be able to view the progress in the Upload Status area.
5. In Upload Complete dialog, click OK. You will see the new version appear on the page. 
Once the upgrade image upload is complete, upgrade verification will start automatically
This verification process will notify you of any potential problems that require intervention from either you or Delphix support. The new version of the Delphix Engine cannot be installed before verification has completed. You can track the progress of verification from the Actions sidebar. If issues are found during the verification process, they will be listed on the version page. An upgrade will not be possible until the issues are resolved.
For more details, see Resolving Upgrade Checks.