Q: how to use iphone 6 plus to set up apple tv

What model number is your Apple TV? You should be able to use bluetooth with Apple's Remote app in the App Store. Here is an article that might help: Apple TV (3rd generation): Using an iOS device to set up your Apple TV - Apple Support

Your Apple TV supports Peer to Peer Airplay (meaning you can set it up via Bluetooth). Make sure Bluetooth is enabled on your iPhone 6. Here is from Apple's website: "Peer-to-peer AirPlay requires a Mac (2012 or later) with OS X Yosemite or an iOS device (late 2012 or later) with iOS 8; and an Apple TV (3rd generation rev A, model A1469 or later) with Apple TV software 7.0 or later". But what is your exact problem? No WI-FI or you lost the remote? Hope this helps

Most school networks require login via webpage, which won't be possible to join as Apple TV has no browser.

vazandrew and tljorda2 you could setup virtualrouter if you have a laptop. It is free here: http://virtualrouter.codeplex.com/ You can then set that up an connect to that if you have a laptop. Hope you get it setup

Not familiar with that, but it looks like Windows only (the OP didn't specify which OS) and saw some concerning things. Have you actually used it? The easiest would be to contact the IT dept

I wouldn't trust that program, better to get in touch with the IT dept for your university