That is totally dependent on the needs of the local USMCR Unit(s). Unlike the Active Marine Corps. the USMCR recruits people that live within 50 miles and a 1 hour drive from the local unit(s). If there are no vacancies for the desired MOS and they cannot double slot you, then there is no waiting list, as they have no real idea when a vacancy might open up.
US Army Recruiter, 1981-1999