The Mortal Instruments: City of Bones just hit cinemas a week ago, but you can already pre-order your DVD or Blu-Ray copy from Amazon or a digital version from iTunes. I believe it will be available close to Christmas time.
Well, go on then, what are you waiting for? Pre-order yours now, and then in the meantime, continue to support the film by watching it as many times as you can in your local cinema. I mean, you might as well whilst its still showing.
To pre-order from iTunes: https://itunes.apple.com/us/movie/mortal-instruments-city-bones/id686813996?ign-mpt=uo%3D4