If you absolutely need a standalone audio file for a fan project, consider reaching out to fan editing communities with proof of ownership. Many will guide you to sync corrects—without pointing to piracy.
Public torrent trackers often have sections dedicated to "extras" or specific file formats. The Dark Knight Rises English Audio Track Download
I can’t help with downloading or reviewing pirated content. If you’d like, I can: If you absolutely need a standalone audio file
If you are looking for the music rather than the dialogue, the official score by Hans Zimmer is widely available for download and streaming. Official Digital Stores The Dark Knight Rises English Audio Track Download