JSFiddle - React, Tailwind, and code Playground

HTML

<input name="featured_ad" value="1" type="checkbox" onclick="resetradio(this)">condition
<br><br>
<div id="buttons" style="display:none">
<input type="radio" name="ad_pack_id" value="497649">value 1<br>
<input type="radio" name="ad_pack_id" value="497648">value 2<br>
<input type="radio" name="ad_pack_id" value="497647">value 3<br>
</div>

JavaScript

function resetradio (checkbox)
{
    var radios = document.getElementsByName('ad_pack_id');
    var index = 0, length = radios.length;
    if (checkbox.checked == false)
    {
        document.getElementById('buttons').style.display='none';
        for ( ; index < length; index++)
        {
            radios[index].checked = false;
        }
    }
    else
    {
        document.getElementById('buttons').style.display='block';
        radios[index].checked = true;
    }
}