JSFiddle - React, Tailwind, and code Playground

HTML

<table border="1" class="table">
        <tbody>
            <tr id="0">
                <td>ID</td>
                <td>Imie</td>
                <td>Nazwisko</td>
            </tr>
            <TR id="1">
                <TD>1</TD>
                <TD>Jan</TD>
                <TD>Nowak</TD>
            </TR>
            <TR id="2">
                <TD>2</TD>
                <TD>Adam</TD>
                <TD>Kowalski</TD>
            </TR>
        </tbody>
    </table>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>

JavaScript

function handler() {
    var trid = $(this).closest('tr').attr('id');
   console.log(trid); 
}
$("tr").mouseover(handler);