sub send_item {
  my ($item, $r) = @_;

  my $fh = $item->{path};

  my $attach_name = basename($fh);
  my $content_size = -s $fh;


  $r->content_type($item->{mimetype});
  $r->set_last_modified;
  $r->set_content_length($content_size);
  $r->headers_out->set('Accept-Ranges' => 'bytes');
  $r->headers_out->set('Content-Disposition' => "inline; filename=\"$attach_name\"");
   
  #After commenting below 2 lines also not getting 206
  my $ranges = "bytes=0-".($content_size - 1)."/" . $content_size;
  $r->headers_out->set('Content-Range' => "$ranges");

  unless ((my $status = $r->meets_conditions) == OK) {
    return $status;
  }

  return OK if $r->header_only;
  $r->sendfile($fh);


  return OK;
}

##</code><code>##

Output filter dump:
--------------------
output_filters: 0(byterange)
output_filters: 1(content_length)
output_filters: 2(http_header)
output_filters: 3(http_outerror)
output_filters: 4(log_input_output)
output_filters: 5(core)