Book Upto 12 tickets in a month online by linking Aadhaar.https://t.co/2aINzba9Ml
— Ministry of Railways (@RailMinIndia) November 3, 2017
How To Link Your IRCTC Account With Aadhaar Number
The process for linking Aadhaar with your IRCTC account for booking train tickets is simple. It can be done online.
Go to IRCTC e-ticketing website and after you log in with your id and password, go to My Profile tab

From that select Aadhaar KYC
Then you will taken to a page where you will be asked to enter your Aadhaar number

Enter the Aadhaar number and you will receive the Aadhaar OTP for verification.
After you enter the OTP, your IRCTC will be Aadhaar-verified.

You will receive a message that "KYC details have been updated successfully".
IRCTC says At least one passenger on the ticket being booked, beyond 6 tickets in a month, should also be Aadhaar verified.
Users are required to verify the probable passengers through their respective Aadhaar
number and store the verified passengers in passenger master list. This should be done
before starting the ticket booking process, beyond 6 tickets in a month, says IRCTC.
User can add Aadhaar verified passenger from master list at the time of booking to book
additional tickets up to 12 tickets in a month, IRCTC adds. IRCTC has shared a document for users who want to book between 6-12 tickets a month.