Thanks for the information @Paul09. I think if they refuse it, he can apply under HCC for consideration. I remember one of my friend got affidavit from his sister to support for his parents, just have to confirm with him again. It could be possible or maybe not.Ask him need not to worry, just wait for the results on sponsorship application and him to try to achieve the minimum income requirements from now on. If the result is positive, means he got the SA keep the income level above required until parents application approval. If for some reason, ircc refused the case, ask him to appeal the case under humanitarian guidelines. If they are only 2 child and both are in Canada as permanent residents they can appeal the case and ircc will give them positive decision. Hiring a good lawyer will help.