1.Add this line into functions php <?php require_once('/categories-tabs/index.php'); ?>
2.Add this code the place you want to display categories_tabs
<?php echo display_categories_tabs_html(array("postsCount"=>"5","containerWidth"=>"300px","tabsBorder"=>"3px","tabsBackground"=>"#fff","tabsHoverBackground"=>"#a9d300","tabsColor"=>"#444","tabsHoverColor"=>"#000","contentBackground"=>"#fff","thumbnailWidth"=>"100px","thumbnailHeight"=>"100px")); ?>