Im 6 feet tall, 33" inseam, what is my mtb frame size?

You should be anywhere from 19 to 21 inches in frame size. But be sure to get fit from a bike shop. Proper fit is crucial. Are you thinking about loaded touring? If so, I would caution against a mtb with front suspension. The fork simply adds weight, makes it impossible to carry a load in the front, and makes steering with an additional 50 lbs. on the bike a little awkward. I would suggest a dedicated touring bike or a mtb with a rigid fork and slick tires.

18", 19" or 20". If you are using this for offroading then go towards the smaller frame. If you are on the road or smoother trails then go towards the upper end.

I would recommend you look at a road bike. Mountain bikes and ATBs are not real good for extended on road riding.

We are both the same size and inseam.I am using trek touring bike

52 cm for almost 3 years now and it is absolutely perfect to my size.Good luck and enjoy the ride.

for mtb, the clearance between you and the frame should be atleast 4 inches. so i say you should use either 19" or 20"

get thee to your local bike shop and get fitted

this will ensure miles of comfortable and safe riding