JSFiddle - React, Tailwind, and code Playground

HTML

<div>
<table>
    <tr id="test1"><td><input type=radio /></td></tr>
    <tr id="test2"><td><input type=radio /></td><td><input type=text /></td></tr>
    <tr><td>
     <table>
         <tr><td></td></tr>
          <tr><td></td></tr>
    </table></td>
        <tr id="test3"><td><input type=radio /></td><td><input type=text /></td></tr>
<tr><td>irgendwas</td></tr>
<tr><td>irgendwas</td></tr>
<tr><td>irgendwas</td></tr>
</table>
</div>

JavaScript

$(':radio').click(function(){
     var tr = $(this).closest('tr'); // zeilen objekt tr[0]
     var tr_index = tr.index(); // zeilen index
    
    // tests
     console.log(tr_index);
     console.log(tr[0].id);
});