If you're going through normal route (MOH clinic etc.) you'll need to register very early. Otherwise they won't accept you.
If you're going through a VOG (Private channel-->Clinic referral), that's a different story.
2 * Visitor pass issued per patient.
If you want to go to the labour room/Operation theater, that won't be allowed. We only have common labour rooms and common OTs in Sri Lanka. Go to a Pvt. Hospital.