It really depends on your school, but know what the GPA requirements are (and what transfers as it applies to that GPA), know if you will need recommendations or not, take advantage of any opportunities to meet the girls prior to rush and be willing to join that chapter that may not be the most prestigious on campus. And if everything works out in your favor, it could happen. Even at the most competitive school they CAN take juniors, but you really better be a catch for them to take the leap of faith with you. Do a search about rush at that particular school. That should give you an idea of what to expect.
"Protect your dignity." Mariam Behnam