Here's the fanart page: http://fanart.tv/movie/49207/r/
I found it by searching for the alternate title “R: Hit First, Hit Hardest” which I found on IMDB by clicking the release date at the top (17 June 2011 (USA)) which takes you to a page that shows the release dates and AKAs.
You could also find the movie ID by searching for “R” on http://www.themoviedb.org/. Once you find the movie and go to the movie's page, the ID is in the address bar as part of the URL, after the last forward slash and before the dash. Just plug that ID in after http://fanart.tv/movie/
Search by id ?
Re: Search by id ?
Or go to the Movie section (Artwork/Movies) and above the main page image there is an A - Z, just click on R