linux-headers-6.1.0-18-common-rt - 6.1.76-1 main

This package provides the common kernel header files for Linux kernel
version 6.1.0-18 with the PREEMPT_RT featureset, generally used for
building out-of-tree kernel modules. To obtain a complete set of headers
you also need to install the linux-headers-6.1.0-18-(flavour) package,
matching the flavour of the kernel you intend the build for.