Finding a stock bike from a mainstream bike company that will fit you is going to be a challenge. Most mainstream bikes in the largest sizes are made for about 6’4″ tall persons. If you find one of the largest size bikes and put on an extra-long stem, seatpost, and crankarms, you might get a bike to fit. However, you would likely need to do this in a bike shop to be certain of the fit.
Reach is not the best indicator of size. Instead, I would compare toptube length to detetmine the longest (or biggest) size. You definitely want to be looking for the longest bike you can find. You will likely find that Enduro type bikes (and there are Enduro hardtails also) have the longest top tubes and will therefore provide you with the best chance of finding a bike that fits. When you’re searching the internet to find that very longest bikes, use toptube length.
I would also suggest the you look at bikes with 29×3.0 tires (or 27.5×4.5 tires if you go Fat). I think you will be most comfortable with the tallest wheels you can get which is 29+ or 27 Fat. At least, try to find a bike with 29×2.6 tires. Some 29×2.6 hardtails I like are the Specialized Fuze and Norco Torrent HT.
Check out DirtySixer.com which specializes in bikes for very tall people. They make 36″ wheel bikes with huge price tags. A Dirty Sixer might be a great bike for you, if you can afford one?