Un array - colocar un br cada 3 item

[gerry18_2]

Disculpen no puedo adaptarlo a este codigo con BASE DE DATOS . me podrian ayudar porfavor?
de antemano muchas gracias

Código PHP:

  <? 
 
$sql="SELECT * FROM producto where estado=1"; 
$res=mysql_query($sql); 
$numero = mysql_num_rows($res);     
$i = 0; 
$row = 0; 
 
 
while($registro=mysql_fetch_array($res)) 
    { 
     
 
?>     
                                                             
                                             
 
                                                <div class="col-3"> 
 
                                                    <div class="indent1"> 
 
                                                        <h5><? echo $registro["producto"]; ?></h5><br> 
 
                                                        <img alt="" src="<? echo $registro["imagen1"]; ?>" class="img-indent" width="135" height="125" /><br> 
 
                                                        <strong><? echo $numero; ?></strong><br> 
 
                                                        <b>Precio: <span><a href="#"><? echo $registro["precio"]?></a></span></b><br> 
 
                                                        <? echo $registro["cantidad"]?> En Stock 
 
                                                    </div> 
 
                                                </div>     
 
 
                                                 
                                             
                                                 
                                                 
                                    <? 
                                 
                                                         
                                                        } 
                                                    ?>