Solution 1 :

This is possible with the <fieldset> and <legend> elements.

legend {
  margin: 0 auto;
}
input {
  width: 100%;
}

<form>
  <fieldset>
    <legend>Comment</legend>
    <input type="text" placeholder="Add your comment"/>
  </fieldset>
</form>

Problem :

I need to make something like this container which has a border and centered caption.

The

thanks for downvoted, but already I used

element but it appears without border.

Please include your HTML and CSS as part of the question to show that effort.

Thanks, buddy but the border doesn’t appear.

Please include your HTML and CSS as part of the question. It’s impossible to help you otherwise.

This doesn’t centre the legend in Firefox. If you use

Thanks @Alohci. I’ve edited to make that improvement.