how to get in in cob?

I want to participate in Spring Rush but I heard that you need to be friends with girls in the houses you want if you want a chance. Is this true? I have barely met any girls in greek life because they all stick together so I'm trying to figure out if it is even possible to meet and become friends with them if it's really neccesary. I really want to be in a sorority since I didn't have a chance in the fall. The two I like the most are Pi Phi and A Phi but I heard these are the most popular so they might not even be participating in Spring Rush...