There is a way to get the Patch Levels direclty from the vendor
but you do need to use the AIX downloader if you have installed your VPC In offline environment, the downloader is the only option to populate the AIX policies directory that contains a filesets.txt for each PATCH level requested.
ALso, you again need the option of downloader to generate the metadata (called .deps files ) for each patch.
In a way, if this is offline environment , you *have to* use the downloader in one or the other way
How are you trying to use the VPC AIX funcitonality ?
What is your patching strategy for AIX ? Which patch levels ?