AFAIK Pi 3 supports aarch64, so ... maybe? But AFAIK RHEL is probably targeting commercial servers first. But maybe a CentOS/SL for Pi 3 wouldn't be out of the question. The tricky bit is that Redhat probably doesn't have a market for creating and supporting the Pi 3 boot image. But they've done all the legwork for getting aarch64 support in their distro, so that could be reaped in CentOS/SL once you combine it w/a bootloader.

RHEL for ARM only runs on 64 bit ARM server hardware which supports UEFI and ACPI. Things like the Cavium ThunderX/X2, Qualcomm Centriq/Amberwing, HPE Apollo 70, Gigabyte MP30.

Fairly recent u-boot provides some UEFI APIs, not sure if enough to run RHEL, and as far as I know no ACPI at all. However in general terms RHEL for ARM isn't going to run on RPi-style hardware. (CentOS is quite different, they have a team taking the RHEL work and targeting cheaper hardware).

It’s only compiled for server SOCs I don’t see any indication that raspberry pi is tested or even supported . Not sure if you would want it even if it worked since it’s probably too much for your board .