Hi Sujee,
No problem.

You most probably copied the function name and php does not allow two function definitions with same name in any given scope/namespace.

Here is how you can do it.

/**
 * Register post type for User Content.
 */
function buddydev_register_post_type() {
	register_post_type( 'bp_user_content', array(
		'label'    => 'User Content',
		'labels'   => array( 'name' => 'User Contents' ),
		'public'   => false,
		'show_ui'  => true,
		'supports' => array( 'title', 'editor', 'author', 'custom-fields' )
	) );

	/* New post type*/
	register_post_type( 'post_type_name', array(
		'label'    => 'Label Post Type',
		'labels'   => array( 'name' => 'Plural Label' ),
		'public'   => false,
		'show_ui'  => true,
		'supports' => array( 'title', 'editor', 'author', 'custom-fields' )
	) );
}

add_action( 'init', 'buddydev_register_post_type' );

I hope it helps.

Thank you Sujee.
I will suggest to hold on to update for Ajax Registration. We are revamping it and It will be a lot different in next 10-15 days from what it is now.,

Regards
Brajesh