I have managed to put 2 banner in the middle of the 8 categories k2 with this code in the file defaulft.php. But the problem is that I doubled the banner to dNo final and categories.
I do not see how to fix the error. Deputy image url:

minus.com/i/BtkRDLYemfZA

Thank you very much, I hope you can help

How about setting a counter. If the counter is 0 or 1 display the banners if not then do nothing and proceed with the items.

is that I need to publish it in the middle of the category main page, second picture shows. The only problem I have is that I duplicate the end of the category. This is the code that I have set.
<? php if (($ key +1)% ($ this-> params-> get ('subCatColumns')) == 0):>
<- BANNER 1 ->
<php if (JModuleHelper :: getModules ('banner1')):>
<div style="widht:835px;float:left;margin-left:10px;">
<? php foreach (JModuleHelper :: getModules ('banner1') as $ module) {
miss JModuleHelper :: renderModule ($ module, array ('style' => 'line'));
}>
</ div>
<? php endif;>


<- BANNER 1 ->
<- BANNER 2 ->
<php if (JModuleHelper :: getModules ('banner2')):>
<div style="widht:267px;float:right;margin-right:10px;">
<? php foreach (JModuleHelper :: getModules ('banner2') as $ module) {
miss JModuleHelper :: renderModule ($ module, array ('style' => 'line'));
}>
</ div>
<? php endif;>
thank you very much.

the
will not help you. You can use the $key variable like if ($key + 1) == ' Item number you want'

thank you very much for your help
I do not understand php. then it is not possible to publish banner amid the k2 category as shown in the picture?

Without editing the template it is not possible.

Did the
<? php if (($ key +1 == 4 )):>

did not work?