Not very few, in fact, only 1 cross AF point. BUT:
The whole discussions regarding non-cross AF points as a weakness is overly exaggerated.. And for portrait, I guess you'll have more time to re-adjust focus (or probably re-compose a bit) as necessary. If great photographers using 5D mk1 or mk2 in the past could do it, there's no reason 6D can't do it.
The non-cross AF points will fail if you purposely focus to subjects which contrast is of the same orientation with the AF point. Something like.. pointing a vertical AF point onto subject with vertical contrast only. But then in real life very rarely I came across this situation.. and there's always a focus and re-compose method if you die2 need to do it.
However, since 6D's AF points are not as many & not as densely positioned like D610, D610 will have better tracking capability (at least on paper). And if it's still not enough then probably you need to go with the higher model (for example if you earn living as a sport photographer). Also take note that D610's 9 cross points are all located on the center, not spread around the frame.
FYI I use 6D's outer AF points (non cross) extensively.. coming form 60D, it's hard to remove the habit :bsmilie:
IMHO, both cameras will serve you well, and if you already invested in Canon system, then just stick with Canon (unless you don't mind offloading your gears and spend more on a different brand).