just add width height not in style            <iframe class="map"  width="510"  height= "510" src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d367298.85638395866!2d76.72027160297871!3d8.824467905511694!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x3b05dc75a70fa0c3%3A0x5e9601dca63dd3fb!2sPMSA%20College%20kuttikadu%20kadakal!5e0!3m2!1sen!2sin!4v1643646588236!5m2!1sen!2sin"></iframe>