A provincial nominee program is an immigration class run by each province in order to bring those they feel they need. Ontario does not have a program that allows you to sponsor adult brothers and sisters so forget that.
They either have to apply on their own or at the most, you may be able to help them get a job offer which will help them either apply for their immigration or get a work permit. They should have graduated something and have at least a couple of years work experience before they can apply.