When a gang application is made, first of all it is reviewed by the (A)Gang Management. If the application is good, he processes it to the stage "Community Feedback" on that application (this doesn't include applications which didn't succed through this process). If an application gets as much as 18 supports with a valid reason, the application is a success and is accepted. If the application gets at least 10 unsupports, with a valid reason,the application will be denied.
REMINDER: When you support a Gang Application you HAVE to write a reason why you like it and why you support it. Same goes for the unsupporting.