From the 1903 NSW Electoral Roll for BLAND, polling at Wagga
PORTER
Elizabeth, Docker Street, domestic duties
James, Beckwith Street, brickmaker
James, Docker Street, labourer
John, Docker Street, labourer
Robert, Docker Street, labourer.
So, if I speculate that John and Robert are both sons of James, then I need to mention that to enrol to vote, they needed to be at least 21 years of age (1903 minus 21 equals 1882)
I cannot see a NSW birth registered for Robert PORTER with parents as James and Elizabeth or as James and Ann ( searching 1856-1900).
Cheers, JM