how do I delete a vm that is not showing up in vcac but was provision in vcac? probably a failed provision process but the vm is online in vcenter
Simply delete it from vCenter....
But... I don't know if it also cleans up the database for vCAC.
On the other hand, I don't think it does harm if you remove it from vCenter as vCAC does a reinventory and removes items when they are gone (if I'm correct)
Does the machine show in Infrastructure > Managed Machines? If so, Destroy from there. You need to ensure the logged on users has the correct privileges.