As a part of going green, Indian Railway / IRCTC has launched virtual tickets with the Virtual Reservation Message (VRM) and thus eliminates the need of physical tickets and printouts to travel in the train.
Virtual Reservation Message (VRM) is a screen-shot of the e-ticket displayed through laptops/palmtops/Mobile phone. It has been accepting Electronic Reservation Slip (ERS), which is a regular ticket printout which contains the PNR, name, age and berth details of the passenger.
According to IRCTC, ERS/VRM along with any one of the eight prescribed ID proofs in original and the indication of the passenger(s)’ name(s) in the Reservation Chart will authorize the passenger to travel. VRM combined with valid photo-id in original will be treated as an instrument on par with the ERS.
ERS/VRM along with one of the eight prescribed proofs of identity in original will also authorize the passenger to enter the platform on the day of journey and he/she will not be required to purchase platform ticket. ERS/VRM along with original id proof will be required to be produced on demand of Ticket Checking Staff on the platform.[source]