If he can get a visitor's visa (a TRV) he can come visit you in Canada; people often get a 6-month visa, and they can be extended. But to get a TRV the applicant has to prove he will leave Canada, and this is not easy. The visa officer will want to see ties to his home country or to Malaysia such as enrollment in university, a job with a letter from the boss giving 2 weeks off (for eg.), a mortgage or apartment lease, money in the bank, etc. Even then someone from Pakistan will have a hard time getting a TRV.
If he does manage to get a TRV, then sponsoring him inland would make sense. This way he can stay in Canada while the PR visa is being processed.
If he can't get a TRV, then you will have to sponsor him outland. If he has been admitted to Malaysia for one year (this means the visa he used to enter Malaysia was for a year or more; he doesn't have to have been in Malaysia for a year already) you can sponsor him through the Malaysian visa office, which is much faster than through the one in Pakistan.
People usually think outland is better than inland anyway. With an outland application, the processing times are usually faster, and you can appeal. Inland is faster than outland through Pakistan, though, so if he can get a TRV and you can't sponsor him through Malaysia, I would sponsor him inland.
