Hello,

To center your clients, please add this code into your custom css box:

.clients .item {
  margin-left: 50px;
}

To make open in new tab, please go to file vc_templates/clients.php and find this line:
$output .= '<a href="'.esc_url($client['url']).'" title="'.esc_attr($client['title']).'">';
Replace with this:
$output .= '<a target="_blank" href="'.esc_url($client['url']).'" title="'.esc_attr($client['title']).'">';

Best regards!