Its Dell PERC H730 1GB cache with on board battery backup RAID controller, 8 ports 12Gbps PCI Express (PCIe) supporting 3Gbps, 6Gbps and 12Gbps SAS or SATA hard-disk or solid-state drives.
I think something similar, brand new, costs in the range 1200-1500 euro

there are some suspiciously
too-cheap controllers on Aliexpress and eBay/China for 50-100 euro (WHAT?!?)
but, if no matter how you get your RAID controller and how much you pay for it: will the Linux kernel v6 able to manage the "hardware RAID" engine on non-x86 machines?
This is the main question ... and usually the answer is ...
noOn { HPPA, MIPS, PPC, SH } you can't use the x86-BIOS-extension mechanism, therefore the MEGA-RAID cannot use re-configuring functions, written in x86 assembly.
When you are lucky, you can temporarily plug the card into a x86 Windows/Linux SBC to make good use of the BIOS extension mechanism and re-configure the controller. Usually a text interface appears during booting, and you can scroll and press the enter-key or space-bar to confirm settings.
This, if and only if, there is a NVRAM able to keep the configuration, the battery is OK and the controller doesn't need to automatically reset the NVRAM if it doesn't find an x86-BIOS-extension environment.
plus, sometimes you also get GNU/Linux x86{32, 64}bit binaries as RAID utilities to run-time interact with the controller.
Two possible solutions
- add an x86 emulator in userspace with a door opened in kernel space to execute such a x86 code
- reverse engineer the MEGA-RAID BIOS-extension and x86-utilities to understand which/how registers you have to configure
why is life so complex

?