My parents lived in Canada for about 600 days after they landed. They didn't return during the pandemic. I am their only child. Can I apply for reinstatment of their PR status based on the humanitarian and compassionate reason? Do they need to be physically in Canada during the petition process? Thank you.
The situation isn't quite clear.
Was their PR status officially revoked or did they renounce it? If not, they are still PRs.
Assuming their PR cards are no longer valid and they don't have US visas, they need to apply for PR Travel Documents with H&C considerations. They will need to explain and provide evidence for having failed to meet the residency requirement (i.e., provide an H&C explanation for what kept them out of Canada). Their reasons will need to extend beyond COVID since COVID travel restrictions ended quite a long time ago.
If they have officially lost their PR status because it was revoked or they renounced, then in order to apply for PR under H&C, they must physically be in Canada at the time they submit the application.