CARA 6.8.0 is not certified under RHEL9. What RHEL versions are allowed for CARA 6.8.*.
CARA 6.8.*, RHEL8 and RHEL9
According to System requirements CARA v6.8, CARA 6.8.* are supported under RHEL8.
According to Releaase notes CARA v6.8.1, CARA 6.8.1 and above are supported under RHEL9.
Also, 6.8.0 is expected to work under RHEL9 despite not certified officially.