Is 26cm wheel bike suitable for 5feet 8inch man?

Answer 1

First of all it's probably not a 26 cm wheel, byt rather a 26 inch wheel.

That size is a bit tricky if you have to go looking for spare parts as there are no less than 4 different sizes called 26".

Better to use the millimeter size instead, which for most 26" today is 559 mm.

Secondly, wheel size doesn't tell all about bike size - frame size is every bit, if not more important. At your height, a frame that can take 26" wheels have every chance of being both too big and too small.

I'll add a few links, which I strongly recommend that you check out, but the short answer would be that for a Mountainbike-typ of bicycle, you should probably be looking at a size medium (17-18") bike.