With these apps you can buy tickets online.This app is for online ticket purchase in Bangladesh Railway. Online Ticket Purchase facility is given here. I think this app will be helpful for you.

Easiest way to buy train tickets and the user can buy tickets with their Bkash , Rocket payment options.
Train ticket buy:
No need to waste time waiting in line for buying train ticket anymore. just follow this steps to buy tickets online:
1.Download this app
2. Turn on your internet connection
3. Register your account with your email and password
4. select your favorite day, train, ticket type.
5. Finish payment.
After successful payment, you will receive an email shortly. print out this email and take it with you to the station when receiving the ticket.
This app is for online ticket purchase in Bangladesh Railway. Online Ticket Purchase facility is given here. Train Ticket BD app will help you to fare query of every train in Bangladesh.
I think this app will be helpful for you.
Thanks .