rewrite rule should be:
RewriteCond /home/www/torrent/$1.php -f
RewriteRule ^/(.*)$ /$1.php
You are accessing URL '/', this does not work, you should use directory indexing instead, add "index.php" or whatever index file used to "Directory Indexes". if you access "/index" URL, the above rule will serve it with /home/www/torrent/index.php.