December 1 onwards it would be mandatory for all new four-wheelers to have FASTag devices fixed on front windscreens by automobile manufacturers or authorised dealers.
A FASTag is a device that employs Radio Frequency Identification (RFID) technology for making toll payments directly from the prepaid or savings account linked to it and is affixed on the windscreen of the vehicle and enables the commuter to drive through toll plazas, without stopping for cash transactions.
"...Motor Vehicles sold on and after December 1, 2017, shall be fitted with FASTag as may be specified by the central government, from time to time by the manufacturer of the vehicle or its authorised dealer, as the case may be," a notification issued by the Ministry of Road Transport and Highways said.
The Ministry took to the Twitter and wrote, “#FASTag to be installed on all 4 wheelers from 1st December'17 #NewIndia”
https://twitter.com/MORTHIndia/status/926077344304869376
The notification follows the amendment to Central Motor Vehicle Rules, 1989 by the central government as per powers vested in it under Motor Vehicles Act, 1989.
The notification explained that a FASTag means "an onboard unit (transponder) or any such device fitted on the front windscreen on the vehicle".
The tag can be purchased from tag issuers and if it is linked to the prepaid account then the vehicle owner is required to recharge/ top up the tag as per requirement.
-PTC News