NOC has nothing to do with this, you dont need that, but you need the exit permit. it's to late, it has already been issued by immigration. they dont stamp in passports anymore. its a piece of paper. He will have to ask the company for the need of what's called a "exit for re-entry visa" if he dont want to lose this job.
He will need the company to apply for it. Otherwise, he dont want the job, he can just ask the company for a exit permit and not come back.