If I am recalling it right it is opposite the Uncle seria hospital. Some where in Saddar area. Go there with the RCMP request email, the police officer will get the prints on FBI finger prints card and authenticate it. Once it done send the card to Canada via courier and take it to any finger print agency they will able to convert it to electronically and will sent the request to RCMP for checks.
This information is still correct, just wanted to post it incase if anyone is looking to do FP from Karachi.
I recently did the FP @ Forensics Division, Sindh Police at the following location and then mail it to Canada to
ACE FINGERPRINTING SERVICES(They provided the forms and did very professional job)
V29C+WV9, Gazdarabad Police Head Quarters, Karachi, Karachi City, Sindh, Pakistan