The South Mumbai skyline is the first illustration. In the far right you can see Navy Nagar, in the centre the Air India building and the Oberoi Hotel. To the left of the picture you can see the Ambassador hotel and the apartment buildings on Marine Drive.
This second sketch hasn't come out very clearly due to the distance from which the original photograph was clicked. This is a depiction of the Malabar Hill Skyline as seen from Marine Drive. The photograph on which this drawing is based can be seen in the Mumbai Skylines post, a link to which is given in the paragraph above.
This last image is a pencil drawing of the Worli Skyline, and based on a photograph taken from the Bandra - Worli Sea Link. (A post with several photographs of the Worli Skyline is in the pipeline and so is one on the Bandra-Worli Sea Link.)
Here is a closer view of the skyscrapers at Worli, some of them residential, some commercial buildings.
Related Images: Photos of Mumbai Skylines - Nariman Point and Malabar Hill or Photographs of the Worli skyline: Mumbai Skyline - Worli or Marine Drive Mumbai - Photographs and Sketches or click any of the labels below this post.
If it's more sketches and pencil drawings of high-rise buildings you need, try these posts: Skyscraper Sketches or Sketches of high-rise apartments or Sketch of the Air India building and Oberoi hotel