Are you trying to apply a Host profile or remediate host patches (VUM) ?
For Host patches you need to install the VUM plugin.
A small tip is to download the latest VMware HTML 5 Fling -> vSphere HTML5 Web Client
Run through the setup, once done use the code capture feature, If I remember correctly the latest one will allow you to generate VRO code. Once you have the code capture enabled, run through your process. The code it produces will give you a good idea of what you need to do for your VRO code. If VRO is not an option the powershell code is very simaliar and you can easily deduce the VRO code fom it.
Sometimes it does not generate code like VUM updates, but most of the time it works. I have used this technique for most of my host build automation.
