Once they acknowledge your application as complete you can track it on the BLS website. They will send the application to CGI toronto which takes 1-2 days in theory. After that point you can track your application on passport seva website where you created your PCC request. I got an email when they initiated the police request. Not sure if the procedure is same in all cities but my parents had to go to the police station with their Aadhaar card and stuff. Takes a week or two for them to approve it from their end and send a "clear" status to CGI toronto. The last update would be of your PCC being printed, after which they send that to BLS. lastly BLS will send it via purolator and provide you with the tracking number on their website
I believe in my case also they followed the same process, below are the steps
1. BLS Acknowledge the application
2. Application in Transit to Counsolate (1-2 Business Days)
3. Application status changed to "Your application sent to Police station for verification, once verification is received from police station PCC will be available for issuance" (something like that)
4. Once you see the above status after 2 days if your Indian relatives did not receive any phone call from the local police station, I would encourage them to follow up with the police station that you mentioned in the PCC application this will speed up the process
5. Once they verified the process at the police station it will go back to Counsolate, in my case it took 4-5 business days once police verification is completed at the local police station
6. once it is done your status in passport Seva will change to "your PCC is printed"
7. once this status they will send PCC to BLS and BLS will send it to you via Purolator courier (this takes 1-2 days)