Check if a post has term inside loop

Since you’re dealing with custom taxonomies, you must mention that custom taxonomy in has_term().

if ( $prr_query->have_posts() ) {
    while ( $prr_query->have_posts() ) {
        $prr_query->the_post();
        if (has_term('proteger', 'prr')) {
          the_title();
        }
    }
}

Source