Why is number 33 the highest rank in Masonic Degrees?

Answer 1

I am guessing that by "ranking" you are referring to degrees. To make a long story short, there is no degree in Freemasonry higher than that of Master Mason, or the Third Degree.

There are, however, a number of organisations (or appendant bodies) that require being a Master Mason as a prerequisite for membership. The Scottish rite is one of these appendant bodies and offers degrees up to the thirty third.

While these appendant bodies have no authority over Freemasonry, (nor regardless of the level of their degree, do they place their members in a "higher" status than that of a Master Mason) they can provide an expanded perspective on some of the allegorical, moral and philosophical aspects of Freemasonry.