a) You can make photo using digital camera/ webcam or you can scan the physical photograph you already have.
b) Indian Online Visa photo requirements:
Size: minimum 10 KB – maximum 300 KB
The height and width of your photo must be the same.
To learn more about all steps of application process (here you will also find instruction how to resize your photo) follow this link
Do not worry about the photo size requirements. Visafoto.com guarantees compliance. It makes correct photos and fixes background.