Can you tell me if i could get a cast for my badly sprained ankle?

Yes: Depending on the severity of the ankle sprain casting can be a treatment option. There are several ligaments that hold your ankle together and when enough of them are torn, the ankle can become unstable requiring a cast. In some cases they need to be surgically repaired. In most cases, however, an ankle sprain an be treated with a removable boot although sometimes you still need to use crutches.