The carrier nicknamed Big Red has published the update documentation on its website, which means the rollout of the new software is imminent (if it hasn't started already).
As usual with these things, keep in mind that the over-the-air rollout will be staged, so it might be a few days (or more) before your Note 4 tells you about the update. If you don't want to wait, you can try to manually check by going to Settings > About phone > Software updates.
Your battery will need to be at least half full to initiate the procedure, and you are required to have at least 1.7GB of free space available. After applying the update, you'll be on build LRX22C.N910VVRU1BOAF.