How i can add ‘N’ page of ‘N’ pages under posts loop?

You can get the current page number by get_guery_var('paged')
If it doesn’t return value, it is 1’st page.

To get the number of total pages, you need to get the total number of posts and divide by the number of per_page. Or you can simply use max_num_pages of $wp_query object.