Q. My height 5'6', is Unicorn 150 suitable for me?

With shoes both leg will stay comfortably on ground. but even if only one foot is touching the ground, any bike will be comfortable once you get used to it. more than height, look at weight of bike..

If you are a new gen design admirer, go for X blade. Apart from the new gen model series, I would be happy to suggest you unicorn 150 ABS(NOV 19) for every other reasons. so in my suggestion go for unicorn 150.

If you have experience in riding bike, then height won't be a matter. But if you don't have, then you should consider arranging a testride to confirm it.