There are all types of videos available on installation of the Fastag in the car, and many of these do not get it right. So, here is a list of steps you shall take while placing it on car.
1. It has to be placed from inside of the car and on front windscreen.
2. You shall place it on left side of rear view mirror (IRVM), while sitting on co-driver seat.
3. If your car windscreen has black border film, it shall be placed clear from it.
4. It shall also be placed clear from the V-shaped ceramic line.
5. It shall be clearly visible from outside.
6. Do remove all dust and oil from inside of car before pasting it.
Below pictures will make things clear on where to place this from inside the car.
Front view of correct placement on windscreen of car
Inside view of correct placement of Fastag