If($Post_media != ''){

Question

If($Post_media != ''){

echo '<div class="col-md-4"><div class="post-media">';
echo wp_kses($post_media, $blokco_allowed_tags);
echo '</div></div>';
}
if($post_media != ''){
echo '<div class="col-md-8">';
} else {
echo '<div class="col-md-12">';
}
echo wp_kses($cat_meta, $blokco_allowed_tags);
echo '<h4 class="post-title"><a href="'.esc_url(get_permalink()).'">'.get_the_title().'</a></h4><hr class="fw">';
?>