Hi @Zet Man
i have resolve the issue, but i have 1 problem left.
how do i use an icon for menu?

Your component is missing a page handler.
Study the code and structure of the TETRIS game component. That's a simple example and you'll get an idea.

I am not trying replacing the OSSN custom index
i want a plugin to use a custom page for it's page
here's my code .
For ossn_com.php

    <?php

function hellos_init(){
	$hellos_url = ossn_site_url()."hellos";
	$icon = ossn_site_url("components/hellos/images/hi.png");
    ossn_register_sections_menu("newsfeed", array(
            "text" => "Hello World",
            "url" => $hellos_url,
            "section" => "links",
            "icon" => $icon
        ));
	
	ossn_register_page("hellos", "hellos_page");
}
function hellos_page(){
  	$title = "Hellos";
    $contents = array("content" => ossn_view("components/hellos/index"));
    $content = ossn_set_page_layout("contents", $contents);
    echo ossn_view_page($title, $content);	
}
		
ossn_register_callback("ossn", "init", "hellos_init");

?>

and my index.php

<?php

echo "Hello World";
?>

Pardon? It's not quite clear what you are trying to achieve.
A component may replace Ossn's default index.php. Yes. But it's completely up to YOU what code you're putting on it. :)