Corentin

The Breton pronunciations are either /ko.ʁɛn.tin/≈"kaw-REN-tin" (in Nothern and Western Brittany) or /ko.ʁɛn.tin/≈"kaw-ren-TEEN" (in Southern Brittany).
The French one is /ko.ʁɑ̃.tɛ̃/≈"KAW-RAH^N-TEH^N" (quite difficult for people who don't speak French as there are three very special sounds : /ʁ/, /ɑ̃/ and /ɛ̃/).
In all those cases the "R" is the French/Breton/German /ʁ/. [noted -ed]

I do know how it's pronounced, but it's hard to explain. Kind of like Ko-ro-TAWN (at least in French). First I thought it was weird, but now it's growing on me.