@fizzmon you if it is before December 1st, the player can be signed and play that year. He would have an increased cap hit for the first year since he is due the full years contract in a shorter time span (if regular season has already started)
If it is after December 1st, the player cannot sign until July 1, where he is still an RFA
The player can agree to a contract with other teams (you can then either match (sign player) or decline (release player)), however offer sheets never happen from CPU teams, so you won't have to worry about this