samdo,
 
<!DOCTYPE HTML>
<html>
<head>
    <title>Untitled</title>
    <meta charset="utf-8">
    <style type="text/css">
        .tabcontent {
            display: none;
        }
        .tabcontent.show {
            display: block;
        }
    </style>
</head>
<body>
    <div>
        <div id="tv1" class="tabcontent">1
            <img src="./img/img1.jpg" alt="">
            <img src="./img/img2.jpg" alt="">
        </div>
        <div id="tv2" class="tabcontent">2
            <img src="./img/img3.jpg" alt="">
            <img src="./img/img4.jpg" alt="">
        </div>
        <div id="tv3" class="tabcontent">3
            <img src="./img/img5.jpg" alt="">
            <img src="./img/img6.jpg" alt="">
        </div>
    </div>
    <script>
        var slideShow = function(container) {
            this.images = container;
            this.curImage = this.images.length - 1;
            var nextSlide = function() {
                this.images[this.curImage].classList.remove("show");
                this.curImage = ++this.curImage % this.images.length;
                this.images[this.curImage].classList.add("show");
                window.setTimeout(nextSlide.bind(this), 5000);
            };
            nextSlide.call(this);
        };
        var slike = document.querySelectorAll("#tv1, #tv2, #tv3");
        slideShow(slike);
    </script>
</body>
</html>