1. Find file called functions.php in your theme folder and add the code in it.

if ( function_exists('register_sidebar') )
    register_sidebar( array(
   'name' => __( 'Homepage'),
   'id' => 'homepagearea',
   'description' => __( 'Widget area for your site homepage', 'twentyeleven' ),
   'before_widget' => '<aside id="%1$s" class="widget %2$s">',
   'after_widget' => "</aside>",
   'before_title' => '<h3 class="widget-title">',
   'after_title' => '</h3>',
   ) );

2. Place this code in the div or any other container you wish to display you new custom widget area.

<?php 
 // Custom widget Area Start
 if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('Homepage') ) : ?>
<?php endif;
// Custom widget Area End
?>

That’s all.