I want to create a search option for CPT using plugin. The search options should search for categories and tags

Did you add your cpt to the search query ?

function include_cpt_in_search($query) {
  if (is_admin() || !$query->is_main_query())
    return;

  if ($query->is_search) {
    $query->set('post_type', array('post', 'page', 'your_custom_post_type'));
  }
}
add_action('pre_get_posts', 'include_cpt_in_search');