Checking RHEL 7.6 version for upgrade

Hi

I'm doing my first upgrade of a RHEL 7.6 (Maipo) from 7.6 to 7.9, then use LEAP from 7.9 to 8.6

How do I check that the system is OK to upgrade from RHEL 7.6?

These servers were installed by a Vendor for its product, and I'm hoping they didn't use a cut down/modified version of RHEL 7.6

How would I be able to run a check/test to see if the 7.6 to 7.9 upgrade process should run OK please?

Thanks in advance.