You may sponsor your dad and/or mom, while they have valid temporary status in Canada. However, keep in mind that visitors are a class of temporary resident who are legally authorized to enter Canada temporarily for holiday, visit family, conduct business, etc. They are restricted in length of stay and are subject to various other conditions. If you are considering a status extension request, you should always apply at least 30 days before current status expires. Please note, it is illegal o remain in Canada beyond the validity of issued status in Canada.