for my $i (0..$#fs_list) {
   if ($i % 6 == 0) {
      ... div ...
   }

   ... $fs_list[$i] ...
}
[download]

or

... div ...
for my $i (0..$#fs_list) {
   ... $fs_list[$i] ...

   if ($i % 6 == 0) {
      ... div ...
   }
}
[download]

depending on what you want