JSFiddle - React, Tailwind, and code Playground

HTML

<div id=box-1>
<table>
<tbody>
    <tr><td><input type=radio name=findemich1 /></td><td><input type=text /></td></tr>
    <tr><td><input type=radio name=findemich2 /></td><td><input type=text /></td></tr>
    <tr><td><input type=radio name=findemich3 /></td><td><input type=text /></td></tr>
<tr><td>
       <table>
           <tr>
             <td></td>
          </tr>
           <tr>
             <td></td>
          </tr>
       </table>
</td></tr>
    <tr><td><input type=radio name=findemich4 /></td><td><input type=text name=testname /></td></tr>
<tr><td>irgendwas</td></tr>
<tr><td>irgendwas</td></tr>
<tr><td>irgendwas</td></tr>
</tbody>
</table>
</div>

JavaScript

$(':radio').click(function(){
     var tr = $(this).closest('tr'); // zeilen objekt evtl. tr[0]
     var tr_index = tr.index() + 1; // zeilen index +1

    // POC
    alert($(this).attr('name') + ' befindet sich in Zeile '+ tr_index);
});