JSFiddle - React, Tailwind, and code Playground

HTML

<div class="list">
        <input type="radio" name="b1" value="1">
        <input type="radio" name="b2" value="2" checked="checked">
        <input type="radio" name="b3" value="3">
    </div>
            
    <div class="list2">
        <input type="radio" name="b4" value="1">
        <input type="radio" name="b5" value="2">
        <input type="radio" name="b6" value="3">
    </div>

JavaScript

alert($('.list input[type="radio"]:checked:first').val());
alert($('.list2 input[type="radio"]:checked:first').val());