In Tourneys I'm using Harrington M-ratio to determine actions and opponent ranges.
My question is should I use Effective M with 9-Max full ring tables (using a 9/10 factor), or I should just use raw M instead?
I think that using raw M is the way to go. Like it says in the wikipedia article that you linked, it is assuming that 10 is a full table. if you are playing 9-max, 9 would be a full table instead of 10. In the equation you would replace the 10 with a 9, and assuming that every seat at the 9 handed table is full, you will be using the raw M.