How to use wp_query in different column in single loop

If you want to display the first post from the loop using a different HTML than the rest of posts in the loop just use a if/else statement.

$post_count = 0;

if ( have_posts() ) {

    /* Start the Loop */
    while ( have_posts() ) { the_post();

        if ($post_count == 0) {

            // Display 6-wide column
            // This will be executed just once for first post.

            $post_count ++;
        } else {

            // Display 3-wide posts
        }
    }
} else {
    // No posts
}

Is that the problem you encountered or did you mean something else?