To integrate in MVC, You can divide code in 2 sections. And put first in controller and pass the $out variable to view, where you can render it with rest of JS/CSS files.

### CONTROLLER PART

include("inc/jqgrid_dist.php");
$g = new jqgrid();
…..
$out = $g->render("list1");

### VIEW PART

<link rel="stylesheet" type="text/css" media="screen" href="js/themes/redmond/jquery-ui.custom.css"></link>
<link rel="stylesheet" type="text/css" media="screen" href="js/jqgrid/css/ui.jqgrid.css"></link>

<script src="js/jquery.min.js" type="text/javascript"></script>
<script src="js/jqgrid/js/i18n/grid.locale-en.js" type="text/javascript"></script>
<script src="js/jqgrid/js/jquery.jqGrid.min.js" type="text/javascript"></script>
<script src="js/themes/jquery-ui.custom.min.js" type="text/javascript"></script>

<div style="margin:10px">
<?php echo $out?>
</div>

How can i integrate with CodeIgniter?

It works in same way. Controller part in controller, view part in view.
Perhaps you already done it as discussed in chat.
Closing it.