The university offer is provided through registration. But for halotel you can buy halotel sim card which is already created special for university offer. To get halotel university offer you can deal *148*55#.
For vodacome registration of University offer you can register yourself by using the ling below
Click here To Register
Further more you can register any VodaCom Sim card through VodaCom agents or by Visiting Vodashop
But about Tigo you can register any Tigo Sim card by visiting to Tigoshop or any Tigo agent who found near of you. To get Tigo university offer deal *148*01*20#.
The same applied to airtel, you can vist Airtelshop or any agent for regisration of your Airtel sim card. To get unversity offer deal *149*81#