Does he have any other documentation that he can THINK to add? Not knowing what he provided as proof from your description it is hard to suggest. If his NOC is still not filled, he can strengthen his application and reapply. If you read his documents, not knowing him at all, would YOU be convinced he carried out the duties of his NOC? Does he have the sufficient education and IELTS score to do the job? Are his reference letters supportive of the duties under that NOC? What questions are raised in your mind? Figure that out and you may be able to help him succeed. If he hasn't sent in enough documents what grounds can he appeal on? Submitting a new and improved application would probably be faster than appealing. At least with a new application, he has a chance to make improvements. Go to this site for information on making a case specific request
https://dmp-portal.cic.gc.ca/cicemail/intro-eng.aspx?mission=new%20delhi
Good Luck to you both.