Vegas Pro in general supports 8 bit, 10 bit (HDCAM SR, X-AVC, CineForm, Sony YUV/V210, ProRes, HEVC, DPX), 12 bit (RED) and more (EXR, DPX) but it is dependend on the video framework. It's not at all limited to 8 bit. But for the Avid Codecs there is no way to access more than 8 bit in Vegas Pro, yet. At least I have no infos this changed.
JesusSheep-1965, hold up a minute there.... Yes Vegas has its limitation, and nothing is wrong with constructive criticism, but don't start with the rude and sarcastic posts.