growing together in the same house?

So say 2 patients live together can they veg 6 plants and flower 6 plants at once? Is it legal to have a coop grow operation?

Yes, it's legal for 2 or more patients to grow under the same roof as long as they are within their limits. Patient coops are okay. Caregiver coops are not.

How many patients can grow in same area, say like 5+ patients want to can they?

So as long as its unique patients and tending on operation they are ok

I personally would never risk going over 99 total plants (including clones/cuttings/moms) in any one grow location. If it is going to be more than just you and your significant other growing together in your house, or a group of roommates in the same house, I would retain an attorney. If you are going to band 16 patients together and grow 96 plants, you should all throw down on a retainer. I'll bet a lot of good lawyers would be interested in helping you since patient coops are fairly uncharted territory.