The demonstrators waved signs such as "Self Defence Is Not a Crime" outside Manukau District Court when Virender Singh faced two charges of injuring with intent to injure.
It followed an brawl involving drunken youths outside his liquor store in Otara in September.
Singh claims he was forced to defend himself after an attempted robbery at his store.
Singh's lawyer Sanjay Sharma told the court that his client would be defending the charges.
Supporters said Singh was totally justified in his actions and called for tougher sentences on criminals.
Singh was further remanded on bail for another pre-depositions hearing on December 3.