Check if child entries exists
If I figured out correctly what you want to do - this should do the trick:

{% if entry.children | length  %}

    &lt;div class="section bg-pattern"&gt;
        &lt;div class="inner"&gt;
             &lt;div class="col-24 gutter-bottom--half"&gt;

                &lt;h3&gt;Available {{ entry.title }}&lt;/h3&gt;

                {% for child in entry.children %}
                    &lt;p&gt;{{ child.title }}&lt;/p&gt;
                {% endfor %}

            &lt;/div&gt;
        &lt;/div&gt;
    &lt;/div&gt;

{% endif %}


entry.children is an alias for entry.getDescendants(1) which returns ElementCriteriaModel