If the original poster wants to play commercial BlueRay DVD movies on the Mac there is NO direct option far as I know.
The reason for this is the very draconian hardwired copy protection schemes employed with BlueRay that Apple didn't go along with, in fact Steve Jobs called BlueRay "a bag of hurt".
But you can take advantage of 3rd party software like Macgo Mac Blu-ray Player, but you have to prepare Blu-ray drive by yourself. There are several available including models from Buffalo, Samsung, LG, ASUS and Sony.