Thats a good question..
There are two cases here
1) Applying for PCC with the same address you have on your passport
- For this you just have to get your passport copy. that is sufficient. Physical Police clearance was waived here because, police clearance was already done while issueing Passport .. But all the applicants who applied along with me, got their PCCs on the same day which was a VERY BIG relief for me ..
2) Applying for PCC with different address which you have on your passport
- Physical police clearance may be required here.. I come under this case, but it is waived off (may be because my wife passport has recent address updated)
Let me explain you my case.. Me and my wife have applied for PCC. My old address is X and new address is Y. My passport was updated with X address and my wife passport is updated with Y address and she got the passport few months back. I have provided Passport copy and Aadhar copy.. my wife has submitted only Passport copy .. However we bot got PCC on the same day within 1 hour..
Dont hire any agents for this process.. it is pretty simple ..
PCC through Passport Seva Kendra is the best way.. First you have to register online in Passport Seva Kendra.. then choose Police Clearance Certificate .. fill up online form and schedule time to appear in the nearest Passport Seva Kendra .. you have to pay 500 rupees online.. You will be asked to select the country for which you are applying, then you can select Canada..
Documents you may need are 1) your passport copy 2) Address proof copy .. Get originals along with you
If you are married, you have to log two online forums, one for you and one for your wife.. the site is very user friendly, there wont be any issue, if in case you have any concern, pm me any time