The discretion lies with immigration officers to issue the permit. They can issue the permit for any length of time they deem appropriate in the case, and it's very much a case-by-case approach. The guidelines suggest four months--120 days--as a period of reflection.
As part of the process of interviewing the victim, the officer will look at the situation of the victim. If a victim has just escaped from a trafficker who may well be a member of organized crime and is after the person, the best course may not be to give them a work permit and tell them to find a job; it may be offer them a form of protection. That's part of what is taken into account. The officer can issue a longer permit. The permit would be required to be extended beyond six months in order for somebody to apply for a work permit. If the situation is appropriate, the officer can do that.