England Under-21 manager Gareth Southgate has suggested the quota system is introduced in the Sky Bet Championship to allow young England talent to flourish.
Southgate said in a number of national newspapers: "I understand why Premier League clubs want to bring in the best foreign players but I think there should be a strong emphasis on the Championship being English or British-based players."
Redknapp, whose QPR side are second in the Championship, thinks it would have limited impact in the second tier and must be applied in the top flight as well.
"It's all right putting a quota system in place in the Championship, (but) if you're going to do it, do it across the board," Redknapp told Press Association Sport.
"Most of your players are going to come out of Premier League clubs anyway.
"The Premier League clubs are getting the pick of the kids; the cream of the crop is still going to the Premier League."
The 66-year-old former Tottenham manager was doubtful if such a quota system could now be introduced.
"I think it's going to be difficult to implement that now," he said.
The issue is to be discussed by a Football Association commission established by new chairman Greg Dyke.
Also on the agenda is qualification criteria, something highlighted by the FA declaring its interest in Manchester United's Belgium-born winger Adnan Januzaj, who has Albanian and Kosovan parents.
Whether nurturing or naturalising, Redknapp believes decisions need to be made.
Redknapp said: "The next situation we're talking about trying to make a kid who has come over to try to get into the England team. And he's got no ties to England whatsoever.
"I think we have to make our mind up which way we're going with it all."