Yes a lay person can fight his or her own case without a lawyer. No need for any vakalatnma also. Only a form needs to be filled in.
But if you are unaware of the intricate details of law you stand to lose the case altogether. As the court won't help you in any way.
As far as my knowledge goes This has been ruled by the Supreme Court also.
Anyways if I'm mistaken about this I apologize.