Edit in JSFiddle

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Sunum</title>
<link href='style1.css' rel='stylesheet'>
</head>

<body>

<div class="grid-container">
<div id="googlemaps"></div>
  <div id="map">
    <div class="left-side">
      <div class="a"></div>
      <div class="b"></div>
      <div class="c"></div>
    </div>
    <div class="right-side">
      <div class="d"></div>
      <div class="e"></div>
      <div class="f"></div>
    </div>
    <div class="bottom-side">
      <div class="b1"></div>
      <div class="b2"></div>
    </div>
    <div class="logo-left"></div>
    <div class="logo-right"></div>
  </div>
</div>

    <!-- Include the Google Maps API library - required for embedding maps -->
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDzVWNVDoBdXY6kxdxX4rYuZDkk9VZUsSg&callback=initMap"></script>

<script type="text/javascript">

// The latitude and longitude of your business / place
var position = [27.1959739, 78.02423269999997];

function showGoogleMaps() {

    var latLng = new google.maps.LatLng(position[0], position[1]);

    var mapOptions = {
        zoom: 8, // initialize zoom level - the max value is 21
        streetViewControl: false, // hide the yellow Street View pegman
        scaleControl: true, // allow users to zoom the Google Map
        mapTypeId: google.maps.MapTypeId.ROADMAP,
        center: {lat: -34.397, lng: 150.644}
    };

    map = new google.maps.Map(document.getElementById('googlemaps'),
        mapOptions);

    // Show the default red marker at the location
    marker = new google.maps.Marker({
        position: latLng,
        map: map,
        draggable: false,
        animation: google.maps.Animation.DROP
    });
}

google.maps.event.addDomListener(window, 'load', showGoogleMaps);
</script>
    
    


</body>
</html>
#googlemaps { 
  height: 100%; 
  width: 100%; 
  position:absolute; 
  top: 0; 
  left: 0; 
  z-index: 0; /* Set z-index to 0 as it will be on a layer below the contact form */
}

#map > div { 
  position: relative; 
  z-index: 1; /* The z-index should be higher than Google Maps */
  padding: 10px;
  height: auto;
}


html, body, .grid-container { height: 100%; margin: 0; }

.grid-container #map * { 
 position: relative;
 border:1px solid red;
}

.grid-container *:after { 
 position: absolute;
 top: 0;
 left: 0;
}

.grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr 1fr;
  grid-template-areas: "map map map map map" "map map map map map" "map map map map map" "map map map map map";
}

#map {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
  grid-template-rows: 0.5fr 1fr 1fr 1fr;
  grid-template-areas: "logo-left . . . logo-right" "left-side . . . right-side" "left-side . . . right-side" "left-side bottom-side bottom-side bottom-side right-side";
  grid-area: map;
}

.left-side {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr 1fr 1fr;
  grid-template-areas: "a" "b" "c";
  grid-area: left-side;
}

.a { grid-area: a; }

.b { grid-area: b; }

.c { grid-area: c; }

.right-side {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr 1fr 1fr;
  grid-template-areas: "d" "e" "f";
  grid-area: right-side;
}

.d { grid-area: d; }

.e { grid-area: e; }

.f { grid-area: f; }

.bottom-side {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr;
  grid-template-areas: "b1 b2";
  grid-area: bottom-side;
}

.b1 { grid-area: b1; }

.b2 { grid-area: b2; }

.logo-left { grid-area: logo-left; }

.logo-right { grid-area: logo-right; }