continuous open biding

i dropped, what are the chances for cob or fall rush

If any chapters are below campus total, they'll be eligible to COB. The timing of COB depends on the chapter- sometimes they'll look to quickly add a few to the new pledge class and other times they'll wait until the Fall semester.

Contact the Greek Life office to let them know you're interested in COB and they will pass your name & info onto any chapters who are COB-eligible.

If you dropped because you did not like the chapters who invited you back, you will probably not want to COB because it will most likely be those chapter(s) participating. You don't get cut by top tier during formal recruitment and then get a COB bid. I know it's after the fact, but the best chance most girls have to join a sorority is to stick with freshman formal recruitment and realize ALL houses are great and have sisterhood and social life to offer.