ruTorrent use ./torrents directory for temporary save of .torrent files. You add .torrent file through web-interface (or rss plugin download it) => ruTorrent place .torrent file to ./torrents directory and pass it to rTorrent => if rTorrent accept it, .torrent file will be deleted from ./torrents directory. If not, .torrent file can't be deleted automatically. You can delete it by hands, if you wish.
Also all torrents created by plugin "create" without "start seeding" option will be placed in ./torrents directory.