We are not lawyers, this is not legal advise.
It is your responsibility to discover what law applies to you and how to best comply with it. In case of doubt, consult your Data Protection Officer (DPO) or equivalent.
KRITIS is the German transposition into law of the EU NIS/NIS2 directive. It essentially gives power to the German Federal Office for Information Security (Bundesamtes für Sicherheit in der Informationstechnik -- BSI) to regulate critical entities.
To learn more about how Compliant Kubernetes can help you implement KRITIS, please see BSI IT-Grundschutz.