Two questions: 1.) What Macintosh are you trying to install a SCSI RAID on? 2.) What kind of device do you wish to make a RAID of, and how many of that device? If it's older than a Power Mac G3, then it is supported. If it isn't, good luck finding a SCSI card for a PCI Slot. To set up a SCSI drive, I would strongly recommend a utility called "SCSIProbe". It worked on my 6360 for when I got my NEC CD-ROM going.
Hope you found this response useful, and welcome to the MacMod team.
I am kind of new to the team myself.