I have download and re-installed xcode 6.4 numerous times and everytime I try and open it after it has been verified the icon just bounces for a while and never opens.
xcode 6.4 won't start
Which version of OSX are you running? xCode 6 has known issues running on El Capitan so,
if you're using that that's likely your problem.
no i am still using the latest version of yosemite. i have downloaded and installed every xcode version from xcoe 4 to xcode 7 and none of them open
How long did you wait? I have seen some versions of Xcode "bounce" for 5+ minutes the first time they are run. Does Activity Monitor show processor activity?