Just as announced and expected, Linus yesterday released kernel 6.0 – see LWN or kernel.org for more.
Debian is still on a long term supported version 5.10, with latest updates to that tree from September 28th as you can see on kernel.org. If you need Debian stable with newer kernels (for new machines for instance), there’s always backports which has more current ones. That’s a supported way of keeping the stable branch a bit more current, and unlike the testing branch it includes security updates.