@Ghany
In file:
oc-content/themes/zara/search_list.php
Find code:
<?php while(osc_has_items()) { ?>
Replace with:
<?php $count = 0; ?>
<?php while(osc_has_items()) { ?>
<?php $count++; ?>
<?php if( gmp_strval(gmp_div_r($count, "6")) ) { ?>
... your banner ...
<?php } ?>
There might be problem with part:
<?php if( gmp_strval(gmp_div_r($count, "6")) ) { ?>
I have never tested it, if it does not work, then replace it with:
<?php if( $count/6 == 1 || $count/6 == 2 || $count/6 == 3 || $count/6 == 4 || $count/6 == 5 || $count/6 == 6) { ?>
Rest is on you.