JSFiddle - React, Tailwind, and code Playground

HTML

<div class="items">
   <div class="col">col1</div>
   <div class="col">col2</div>
   <div class="col">col3</div>
   <div class="col">col4</div>
   <div class="col">col5</div>
   <div class="col">col6</div>
   <div class="col">col7</div>
   <div class="col">col8</div>
</div>

CSS

.row
{
    background:red;
    margin:10px;
}

JavaScript

$(function(){
   
    $(".col").each(function(i,v){
        var $row;
        if ((i % 3) == 0){
           $row = $("<div/>");
            $row.addClass("row");
            $(".items").append($row);
        }
        else
        {
            $row = $(".items .row:last");   
        }
        $row.append($(this));
    });
    
});