We are using SonarQube 7.7 on RHEL6. We are planning to update OS from RHEL6 to RHEL7. Before we upgrade OS we want to make sure that SonarQube 7.7 is compatible with RHEL7. We are not yet planning to upgrade to latest version of SonarQube yet.
SonarQube 7.7 is past EOL & no longer supported. In that move you should also upgrade to at least the current LTS, 7.9.4, or the current version, 8.5.1.
Regarding the OS, as you’ll see in the docs, it’s not a question of OS flavor but of Java version that is really important.