BMC CLM does not currently support Ubuntu or FreeBSD OS out of the box. It is possible to write a provider that would all those OS to be provisioned however
As the provisioning's part is taken care by BSA in CLM suite.
BSA supports Ubuntu & FreeBSD VM provisioning.
But i have no iea about the RSCD agents for them.
If the BSA is Capable to perform VM provisioning of these OS's & RSCD agents installers are available for them,
then it can be done as like normal Service Request provisioning.
Which version of CLM you are using right now, there might be version specific workaround?
BMC CLM 3.1