Theme customizer API get functions

I got the solution for this →

     function mytheme_customize_css()
{
    ?>
         <style type="text/css">
             h1 { color: <?php get_option( 'h1_typography' ); ?>; }
         </style>
    <?php
}
add_action( 'wp_head', 'mytheme_customize_css');

This above might not actually be needed.

just put the css element that you want to be effected In the output array:

'output'      => array(
array(
    'element' => 'h1, h2, .header-menu a, .widget h1',
),

I hope this will be helpful to some one in the future.