Mishra The Great,I think either you didnot read my post or you missed the gist.IT IS ADMISSIBLE as a secondary evidence,there isn't even iota of doubt in that. But it is a prima facie presumption,for your benefit, I quote The Indian Evidence Act,"But though the Courts are directed to draw a presumption in favour of official certificates,it is not a conclusive presumption-it is rebuttable".
Notwithstanding the nittygritty,semantics and presumptions ,suffice to say that a certifid copy ,from
PIO or any other designated public authority,is admissible as secondary evidence in the court of law.