Question

how many significant figures does 6.32 have

Answer 1

It has 3

Answer 2

Here's a nice piece explaining how to interpret significant figures for any value you are presented with. It can take a little bit of time to get your head around it, as the answer is not always what your instinct tells you initially!

http://www.purplemath.com/modules/rounding2.htm

In this case though, all of the 3 figures in 6.32 are deemed to be significant.