<!-- Put this script tag to the <head> of your page -->
<script type="text/javascript" src="//vk.com/js/api/openapi.js?146"></script>
<script type="text/javascript">
VK.init({apiId: 6074315, onlyWidgets: true});
</script>
<!-- Put this div tag to the place, where the Comments block will be -->
<div id="vk_comments"></div>
<script type="text/javascript">
VK.Widgets.Comments("vk_comments", {limit: 15, width: "50", attach: false});
</script>

Виджет

<!-- Put this script tag to the <head> of your page -->
<script type="text/javascript" src="//vk.com/js/api/openapi.js?146"></script>
<script type="text/javascript">
VK.init({apiId: 5663442, onlyWidgets: true});
</script>
<!-- Put this div tag to the place, where the Comments block will be -->
<div id="vk_comments"></div>
<script type="text/javascript">
VK.Widgets.Comments("vk_comments", {limit: 15, width: "50", attach: false});
</script>