Why isn't my backup showing when I try to restore it to my iPad?

I tried out the new iOS 9 beta and wanted to go back to the iOS 8.4 after I had tried it. Prior to installing iOS 8.4, I had backed up all my data on iTunes. I did everything and I set it up as a new device. I wanted to restore but my backup wasn't there. I clicked restore backup but my backup was none of them from the list. But when I click iTunes>Prefernces>Devices {from the top bar (Mac)} my backup is there. I deleted all unneeded backups leaving just the backup I wanted but when I went back to clicking Restore backup, it was grey so I could't click it.

Any ideas on how to fix this problem, I really need to get all my data back on my iPad 4.