Under the federal system, you can only sponsor brothers and sisters if they are under 18 or orphaned or if you are alone in Canada, not married, have no family in Canada and have no family elsewhere that you could sponsor such as parents or grandparents, you could sponsor one other relative such as a brother or sister.
If you are living in Alberta, Manitoba or Saskatchewan, you can sponsor a brother or sister under the provincial nominee programs there but only one at a time and you have to meet certain requirements such as having been PR for a certain length of time, having lived in that province for a while, having certain amount of funds as well as the brother or sister would have to meet certain requirements to be sponsored with education, language skills, age etc.
If you are living in Canada, you could also try to use your connections to get your brother or sister a job offer to help with their immigration.
