Betty, are you looking for a city-wide chapter of an NPHC or multicultural sorority? If this is what you are looking for, go to
http://nphchq.org and look up the various sorority chapters. Their local websites may have that information.
If you are looking to join an NPC sorority, then you're out of luck. There's no such thing as a chapter of an NPC independent of a college or university.