Thte fact that you don't know would lead me to believe that your 401(k) account hasn't been set up yet (which is normal for new hires), so you won't be making any contrib on your Oct 31 pay stub.
Hope you can double up in November, especially if you can Roth401(k).
Contributing to both RRSP and 401(k) in the same year
Moderator: Mark T Serbinski CA CPA