JSFiddle - React, Tailwind, and code Playground
HTML
<table><tr>
<td>Akshay Hulyalkar</td>
</tr>
</table>
<input type="button" value="replace me!" id="btn"/>
JavaScript
$("#btn").click(function() {
var text = $("td").text();
var chars = "Aks";
console.log(text);
text = text.replace(chars, '<span style="font-weight:bold; color:#808080;">'+chars+'</span>');
$("td").html(text);
});