Yes, it is possible to overcook prawns in a curry, just like any other type of seafood. Prawns are a delicate protein that cook very quickly, and they can become tough and rubbery if they are cooked for too long. The cooking time for prawns in a curry will depend on whether you are using raw or pre-cooked prawns. If you are using raw prawns, they will need to be cooked until they are pink and opaque, which should take around 3-4 minutes. If you are using pre-cooked prawns, they just need to be heated through for a couple of minutes.