My team is using the 2 stage planetary gearboxes for our mecanum drive system this year. I can tell you that on the basis of speed alone your probably going to want to go with 3 or 4 stages. the CIMs run at around 5000 rpm free speed.
So 5000/(3.67*3.67*3.67)= 101 rpm
Or 5000/(3.67*3.67*3.67*3.67)=27 rpm
Note: Your actual speed may be significantly lower depending on the efficiency of the gearboxes and whether they are "broken in" or not. See
this thread for more info on breaking in gearboxes.
I hope that helped a little. But, as others as stated, in the future You need to be more specific when asking these types of questions.