Do you want to display WordPress Posts from the Specific Category by Category Id?
$cat_id = 3; $args = array( 'post_type' => 'post' , 'orderby' => 'date' , 'order' => 'DESC' , 'posts_per_page' => 6, 'cat' => $cat_id, 'paged' => get_query_var('paged'), 'post_parent' => $parent ); $q = new WP_Query($args); if ( $q->have_posts() ) { while ( $q->have_posts() ) { $q->the_post(); ?>If you want to show posts with category slug instead of category id then
Replace
'cat' => $cat_id,with
'category_name' => 'my-category-slug',