Rangers boss Redknapp signed the Croatian playmaker on deadline day, having previously worked with him at Portsmouth and Tottenham - where he also managed Dutch schemer Van der Vaart.
Kranjcar is now fit after a groin problem delayed his debut and could make his first start for the Championship leaders against Middlesbrough this weekend.
"It gives me the option of Niko playing in behind as a number 10," said Redknapp.
"He's fantastic in there - a little bit like Rafael van der Vaart when I was at Tottenham. It's an option for me.
"Niko can play in that position on the left where he drifts in between the lines, or off the front. He can play a pass and put people in on goal.
"He's a fantastic footballer and I'm pleased to have him."