Solution:
Include paged, documentation: https://codex.wordpress.org/Pagination
<?php
$args = array(
‘cat’ => ‘5’,
‘post_type’ => ‘post’,
‘posts_per_page’ => 6,
‘paged’ => ( get_query_var(‘paged’) ? get_query_var(‘paged’) : 1),
);
query_posts($args);
while (have_posts()) : the_post();
/* Do whatever you want to do for every page… */
endwhile;
wp_pagenavi();
wp_reset_query(); // Restore global post data
?>
Also don’t use query_posts to fetch data in WordPress, consider using https://codex.wordpress.org/Class_Reference/WP_Query.
Please ask WordPress related question here: http://wordpress.stackexchange.com
I hope this helps.