JSFiddle - React, Tailwind, and code Playground

HTML

<input type="radio" name="some[thing]" value="one">
<input type="radio" name="some[thing]" value="two">
<input type="radio" name="some[thing]" value="three">
<input type="radio" name="some[thing]" value="four">
<input type="radio" name="some[thing]" value="five">
<input type="radio" name="some[thing]" value="six">

JavaScript

$("input[value='four'][name='some\\[thing\\]']").attr("checked",true);