Question

¿What is the polite command form of tomar?

Answer 1

Depends on what you want to say, since "Tomar' has two meanings. 
"Tomar", as in drinking and "tomar", as in taking.

I honestly don't think there's actually a formal way of saying tomar. It depends on the sentence & how you want to address the person. 
Ex. Usted se puede tomar el agua? Can you drink the water?
Ahora, ustedes tomaran el examen > Now, you'll take the exam (but in a polite way!)

If you have any more doubts feel free to ask me!