How to jailbreak iPhone 4 on 6.1.3?

I've tried using redsnow but it keeps saying it is missing a key plist or something. Any help would be appreciated!

Sorry to disappoint you but, you will need to downgrade your iphone to be able to jailbreak it. (BTW I faced the same problem to jailbreak my iphone 4)

Check out http://iosuniverse.com/jailbreak and select your device and firmware. If there's a jailbreak available, it will let you know.