Thanks for joining the NUC community.
I understand you would like use the NUC mini PCI Express* card slot with a RAID controller.
I have been checking the links below about tested peripherals and customer tested components for NUC but there is no information about this type of hardware compatibility. The PCIe Mini Card Slot has been tested mostly with wireless adapters.
At this stage, I recommend contacting Startech support for compatibility information with NUC systems:
have you found a working RAID Controller?