Which Linux distribution is best suited for running a real-time, mission-critical security system on a Jetson Orin with JetPack 6, where performance and resource optimization are critical?
That’s a huge topic. I’d separate the two questions. You will never get “hard realtime” from a Jetson, the hardware is Cortex-A, not Cortex-R (this hardware and software is only capable of “soft” realtime; there is actually an NVIDIA partner that does have a realtime dedicated and supported o/s, but I don’t know the details). As for security, that’s a lot of steps, and not just one distribution.
You could check Concurrent out further:
https://concurrent-rt.com/company/news-events/press-releases/jetsonorin/
If you need functional safety (and perhaps there is some “hard” realtime hardware), then you have to go to the Drive hardware and software (related to Jetson, but it isn’t Jetson).