How I register online 24,000 Students over a period of 25 days every year with realtime registration fee

I am webmaster of a large university in Pakistan where Drupal is in use.My employer university every year registers approx 24 thousand students online. The registration website remains active for 25 days every year. The payment method we have deployed is not paypal or credit card based rather a unique prepaid scratch cards based. For the last five years, this system has brought a substantial change in our workflow and our audience just loves it saving a lot of their time and resources.  The total revenue or charges generated from the student fee is around 362,300 US Dollars. All this is efficiently done via Drupal's powerful architecture and sensible use of some contributed modules.

This session will demo the system I have developed and the modules used. Many universities can thus adopt the same system for any kind of online registrations they may deploy in future.