Hi Thang,
I see - your email was quite misleading. Why would you worry about one way tickets unless you are planning on getting your son here after getting SP?
Any way the secure document is simply via courier at your indicated address. CIC mails the work permits in such scenarios.
Now usually they do not ask for medicals for people already here for work or study permits.
Moreover, it doesn't make a lot of sense to me for them asking for medicals while they have already approved the application.
Were there any details asked regarding how to submit those medicals? But normally speaking if they have asked for it, you should provide it.
Lastly, in the above scenario buying one or two way ticket means nothing. Since you are already in Canada probably no body (air line) would even worry about the return ticket part. It might come up when you are on the way back for boarding. But the same applies even if you had purchased a return ticket.
The standard return ticket issue is different from above. That is for a normal visitor who is coming to Canada. Since he is a visitor most airlines ask for them to purchase return ticket for entering Canada and returning on a pre planned fixed date. That does not match with what you wrote above.
Besides, the most important thing is - Even if your son receives the actual study permit by post, the study permit does not allow him to enter Canada (except may be from US). It has to be a TRV - a sticker on passport that has to be applied for separately when you are already in Canada (unless of course you already have a valid TRV). Please note again - a study permit does not allow you to enter Canada, you need a valid TRV for that.
Once you have a valid SP, trv only takes a couple weeks from inside Canada
