Thank you for the great info.
Where should we send the passports to? I'm thinking how should the parents send the passports From home countries? If posting passports is possible at all
Doesn't Passport Request (PPR) letter include the details about mailing address? Must be CPC-Mississauga where your case was processed.
If not, you can ask others who already had PPR from the tracker.
Your parents can send passport by registered mail from home country to the visa office.
No need to be express mail unless you are in hurry to bring your parents here.
Just plan that once passport is sent it may take few weeks. Your parents cannot travel in that time.
You can book their air tickets once the passport is returned with visa.
Congratulations on the successful conclusion of your case.