Tables:

Train (Future/Current & History)
Unique number (PK)
Date (PK)
Number of AC coaches (x18 seats)
Number of Sleeper coaches (x24 seats)
Remaining AC seats
Remaining Sleeper seats
Price (AC)
Price (Sleeper)

Ticket (Future/History)
PNR number (PK)
Date (FK to Train)
Train number (FK to Train)
Booking Agent (FK to Booking Agent ID)
Number of passengers
Coach Type

Passenger (Future/History):
Name
Age
Gender
PNR (FK to Ticket PNR Num)
Berth Number
Berth Type
Coach number

Booking agents (AUTH):
ID(PK)
Name
Card Address
Password

Admin:
Name
ID
Password

Coach Compositions (From Appendix)
Berth number
Berth Type

Notes: To generate PNR: - Consider Train ID, Date of Travel, Coach number and berth number of 1st passenger.

First AC coaches and then sleeper coaches.
Berth allocation is done serially
Number of booking agents is predetermined.
Error if remaining seats < number of requested seats
Use trigger to update availability of seats
Stored procedure to tranfer data from future tables to history