JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />

JavaScript

$(':checkbox').click(
    function(){
        var selected = $(':checkbox:checked').length;
        if (selected == 3)
        {
            $(':checkbox:not(:checked)').attr('disabled',true);
        }
        else
        {
           $(':checkbox:not(:checked)').attr('disabled',false);
        }
    }
);