Can Canadian citizen sponsor his nephew (sister's son) who is 30 years old and has a family (can nephew's family also be sponsored).
No, it is not possible under family class. A Canadian citizen can only sponsor their immediate family (parents, spouse and children, brother and sister if they are under 18) However, your nephew can apply independently (without being sponsored) for another visa for Canada such as skilled worker, temporary worker and student visa. Once your nephew gets permanent residence and moves to Canada, he can sponsor his own family to come to Canada later. if you are living in Nova Scotia and have business then you can sponsor them. or if you dont have any relative in canada (no spouse, no children and no one else) then you can sponsor your nephew and his family.
hope this helps