Between <head> tags:

<script src=""></script>
<link rel="stylesheet" type="text/css" href=""/>
<link rel="stylesheet" type="text/css" href=""/>
<script type="text/javascript" src=""></script>
<script type="text/javascript" src=""></script>

Script:

<script>
$(document).ready(function() {
    var table = $('#example').DataTable( {
        scrollY:        "300px",
        scrollX:        true,
        scrollCollapse: true,
        paging:         true,
        fixedColumns:   {
            leftColumns: 2
        }
    } );
} );
</script>

Table (it has more than 2 rows):

<table id="example" class="stripe row-border order-column" cellspacing="0" width="100%">
<thead>
<tr>
<th>..</th>
<th>..</th>
<th>..</th>
<th>..</th>
<th>..</th>
<th>..</th>
</tr>
</thead>
<tbody>
<tr>
<td>...</td>
<td>...</td>
<td>...</td>
<td>...</td>
<td>...</td>
<td>...</td>
</tr>
</tbody>
</table>

CSS:

/* Ensure that the demo table scrolls */
th, td { white-space: nowrap; }
div.dataTables_wrapper {
    width: 100%;
    margin: 0 auto;
}

Table is working but table has no fixed columns. FixedColumns part is not working.