Whenever I'm posting some content in wordpress publish page it's showing some paragraph tags like <p> and <br/>. That is showing additional space in output. Same with there any solution for this? How you can remove all of the tags?

do this

$my_postid = $post->ID;
$content_post = get_post($my_postid);
$content = $content_post->post_content;
$content = apply_filters('the_content', $content);
$content = strip_tags($content, '<p><br/>');
echo $content;

This happen due to WordPress's wpautop. Simply add below type of code inside your theme's functions.php file

remove_filter( 'the_content', 'wpautop' );

remove_filter( 'the_excerpt', 'wpautop' );

To learn more: http://codex.wordpress.org/Function_Reference/wpautop