Got a response from CHC Islamabad.
• Application form completed with blue or black pen. Please answer Question 01 to 09 carefully and sign at the appropriate space in Question No. 10.
• Proof of Canadian citizenship of one of the parent, in original;
• Pakistani birth certificate(in original), issued by Union Council of the area, showing both parents' correct and complete names, as shown on their Canadian ids;
• Form “Bay” and its certified translation in English OR “Family Registration Certificate”, in original only;
• Two identical photographs, meeting the required specifications. Ensure that the name of the person (whose certificate is being applied for), photographer's detail and date when photograph was taken is mentioned on the back of the photographs. Photographs with staple holes, smudges or taken in automatic booths are NOT acceptable. All other specifications remain the same.
• If you are applying for a late registration of citizenship, you are required to provide a written statement to the fact why you were not able to apply earlier or soon after the birth of the child.