Hello!
The best thing to do in this case is to make all the fractions have common denominators by having equivalent fractions.
For example, if you have 1/2, 1/3, and 4/6, we make them all get common denominators.
1/2=3/6
1/3=2/6
4/6=4/6
Now we can order them.
1/3, 1/2, 4/6
I hope this helps you!