You can sponsor other relatives besides your immediate family members stated above, these may be
Your brother, sister, nephew, niece, grandson or granddaughter, who are orphaned, under the age of 18, and not married or in a common-law relationship
Any other relative if you do not have a spouse, common-law partner, or conjugal partner, or one of the following living relatives below (excluding the person you wish to sponsor) which you could sponsor instead:
a child
a mother or father
brother or sister
uncle or aunt
nephew or niece
and
you do not have any of the relatives mentioned above who:
is a Canadian citizen, permanent resident, Indian (Native, registered under the Indian Act)
have an application for permanent residence that is being currently processed