Migrating specific servers from Satellite 5.6 to 6.1

I am tasked with installing Satellite 6.1 in our infrastructure. As we still have some RHEL 3 and 4 servers lingering, we will be keeping Satellite 5.6 running until those servers are retired.

In the mean time, I am wondering what the best way to migrate ONLY the RHEL 5.x and above servers to Satellite 6.1, preferably with some form of automation. Do the export tools offer the ability to only export a subset of the servers, or will I be stuck manually re-adding each server by hand?

Thanks...