JSFiddle - React, Tailwind, and code Playground
HTML
<div class="selDiv">
<select class="opts">
<option selected value="DEFAULT">Default</option>
<option value="SEL1">Selection 1</option>
<option value="SEL2">Selection 2</option>
</select>
</div>
JavaScript
var $select = $('.selDiv .opts');
var index = 2;
$select.children().eq(index).prop('selected', true);