Absolutely, as long as the requirements for service are met. You have basic recruiting criteria that are deemed as physical fitness and educational requirements. All of the basic recruiting criteria that are required for the regular force and/or the primary reserves would have to be met.
When we talk about a ranger, I would like to clarify that the Rangers have a requirement of service that allows them to not be retired. There's no age restriction other than having to be a minimum 18 years of age when they join. There are no physical or hard medical requirements that prevent them from either joining or being released. That component of it means that, again, they bring unique skill sets. As long as they're contributing towards the ranger patrol, they can in fact stay in.
In order to transfer or go on to the primary reserves or regular forces, they would still have to meet those basic entry requirements.