Simply asking this as birth registration is a must however if you had a child abroad but failed to register due to not knowing it was important how do you register it later. As for late registration, it says you need to have a valid reason and I donβt know if not knowing is a valid reason.
Our parents didnβt know all these laws back then, only realised it now. As for if both parents are Indian, yes. And the child is still a minor and holds no other citizenship.