The Radeon HD 6000 series is on the list of compatible cards so it should be fine.
http://geedorah.com/eiusdemmodi/forum/viewtopic.php?id=295However, the video card is one of the least important parts of the equation for a GroovyMAME setup.
Having a powerful CPU is more important. You want a recent
INTEL CPU with the higher the clock speed the better. Quad-core is also good.