If it's NPC sorority membership you seek, then no, you will not be able to join because you must be enrolled in a 4 year college/university. There you will have to be a full-time student.

As far as non-NPC sororities go, you'd have to check with them and see what their bylaws say.

Until then, please do a SEARCH on GreekChat for non-collegiate sororities. There are organizations you might want to consider because being enrolled in school isn't one of their requirements.

Good luck!