Don't know rules in your country but I guess it is better to attach Letter from your passport office declaring you were issued new passport against lost passport or any such things.
However, if choose the FIR route then what I have known from Pakistani friends is that you get public notary system in your country.
So get your FIR and it's photocopy. Get your photocopy of FIR notarised. Ask them to translate FIR on a Letter Head and also get a an Affidavit on Translators Letterhead. Get both of these notarised as well. So you will have four documents to attach:
1) Original Scanned Copy of FIR
2) Notarised Photocopy of FIR
3) Translators Affidavit on Letterhead (Notarised)
4) Translation of Letterhead (Notarised)
Also, attach a letter of explanation and explain your case to OINP that why you can't present Previous Passport and attached evidences.
I hope this will help. However, anyone from your home country may help you better.