I recently wrote a blog post on the options available for adopting a VM into vCD that's posted here - https://www.paluszek.com/wp/2018/10/23/migrate-vms-and-networking-to-vcloud-director-video-walkthrough/
The easiest part will be the importing task. You will need to figure out how to utilize NSX/networking functionality and how to cut that over.
Thanks so much Daniel.
You could also take a look at vCloud Extender, and vCloud Availability (Not supported on vCD 9.5 yet).
Depending on backup solution, you may need to reconfigure backups and run full backup of all VMs again.