This worked for me. Basically jquery was missing through
<script
src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min.js">
</script>
and the wrong PHP tags. Thanks for that.
You can find the full code below.
<title> Hi all</title>
<link rel="stylesheet" href="https://wordpress.stackexchange.com/questions/295053/<?php echo get_stylesheet_directory_uri()."/js/jstree/dist/themes/default/style.min.css';?>" />
<div id="data">
<ul>
<li>One</li>
<li>Two</li>
<li>Three
<ul>
<li>Bike</li>
<li>Ride</li>
</ul>
</li>
<li>JOKE</li>
</ul>
</div>
<script
src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min.js">
</script>
<script src="<?php echo
get_stylesheet_directory_uri().'/js/jstree/dist/jstree.min.js';?>"></script>
<script src="<?php echo
get_stylesheet_directory_uri().'/js/jstree/dist/tree.js';?>"></script>