Visual Composer template making

<?php

if(!defined('ABSPATH')) die('-1');

add_filter( 'vc_load_default_templates', 'my_custom_template_modify_array' ); // Hook in
function my_custom_template_modify_array( $data ) {
    return array(); // This will remove all default templates. Basically you should use native PHP functions to modify existing array and then return it.
}

function seo_vc_homepage() {
    $data               = array(); // Create new array
    $data['name']       = __( 'Seo Homepage', 'seo' ); // Assign name for your custom template
    $data['weight']     = 0; // Weight of your template in the template list
    $data['image_path'] = preg_replace( '/\s/', '%20', plugins_url( 'images/custom_template_thumbnail.jpg', __FILE__ ) );
    $data['content']    = <<<CONTENT

        /* here is shortcode  */

CONTENT;

    vc_add_default_templates( $data );
}

add_action( 'vc_load_default_templates_action','seo_vc_homepage' ); // Hook in