Checkbox in Search-module

I can not find where it is. Please, step by step.

Go to Joomla Administration, then go to menus and click Top Menu. You will see first item has star for "Home" column. Click that item to enter it's settings.
In right panel you will see "Layout options" where you can locate "#Intro Articles" parameter.

Sorry, I don't see "Layout options" in right panel.

I never received a reply. Question again:

On the front page under the FEATURED PRODUCTS 6 products displayed: 2 lines of 3 products.

I need to have more lines are 3 products. Where can I configure it to be displayed 4, 5, 6, 7, etc. lines?

Open:

components\com_virtuemart\views\virtuemart\view.html.php

you will find this line:

$products = $productModel->getProductListing('featured', 6);

change 6 to number of products you want to show.