my $ary_ref = [
  { value=>1, text=>'val1'},
  { value=>2, text=>'val2'},
];

..
$template->param(
  select = $ary_ref,
  ...
);

### .tmpl
<select>
<TMPL_LOOP NAME=select>
<option value="<TMPL_VAR NAME=value>"><TMPL_VAR NAME=text></TMPL_LOOP>
</select>