gistfile1.txt

function modify_rs_init_code() {

    $custom_init_code = "$('.royalSlider').royalSlider({autoScaleSlider:true,autoScaleSliderWidth:960,autoScaleSliderHeight:850});";

    include_once(ABSPATH."wp-content/plugins/new-royalslider/classes/NewRoyalSliderMain.php");
    if( isset(NewRoyalSliderMain::$sliders_init_code) ) {
        foreach(NewRoyalSliderMain::$sliders_init_code  as $key => $value) {
               NewRoyalSliderMain::$sliders_init_code[$key] = $custom_init_code;
        }
    }
}
add_filter( 'wp_footer', 'modify_rs_init_code' );