Depends on the injury; some are allowed to rehab away from the team but I think it depends on the type of injury.
If it's a season-ender they are allowed to rehab on their own. If it's a short-term IR injury, they probably still attend meetings and are around the facilities a lot while unable to play.
Last season Jamal Adams rehabbed away from the team because it was known he would not be able to return that season.