JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>Bola</td>
        <td>Casa</td>
        <td>Arvore</td>
    </tr>
    <tr>
        <td><input type="text" class='campo' /></td>
        <td><input type="text" class='campo' /></td>
        <td><input type="text" class='campo' /></td>
    </tr>
</table>

JavaScript

$(".campo").on("focus", function ()
{
    var $td = $(this).closest('td');    

    alert($td.index()); //index
})