There is not set form of time period for attaching the ‘L’ (learner) sticker on the car. But RTO rules say that it is preferably up to the time you have finished learning how to drive and are now confident that you can drive on the open road.
Also when driving with the ‘L’ board it is preferable that you drive on the extreme left of the road in India, i.e., the last lane as that is where you are not only safe from fast cars but you can also take a break if you feel tense.
The L board shows that you are learning how to drive and thus warns other drivers about the hazards if they follow you or drive rashly near your car.
