Hi,
At the moment we officially support RA 6.5 on Redhat version 5.5 to 7.2 .
However i do not expect any issue's with running it on redhat 7.3 as it just a minor update.
We have at least some customers running the agents on it.
I will check with the product team when we plan to certify on redhat 7.3 .
Dirk