This name is also used in the Netherlands, but the pronunciation is hard to explain. I guess it's a bit like "rah-GHEL", but with a very guttural gh sound. Almost like a growl, a sound that is common in the Dutch language but few English-speaking people can properly pronounce.
This is also the Dutch spelling of the name and it is traditionally pronounced RHAW-khəl, though these days people often use the English or French pronunciation because the Dutch one is so awful. [noted -ed]