The Hoops currently sit second in the Championship, 10 points adrift of leaders Leicester City and three points ahead of third-placed Burnley.
Redknapp believes that several sides in the division are capable of winning promotion.
"At the moment we are all chasing Leicester who are running away with it a bit, but you never know," he told QPR's official website.
"There are six or seven teams chasing them, and Derby are one of them. This is going to be a very tight division. You look at them, Nottingham Forest, Leicester, Reading, Wigan who have started to put a run together.
"I wouldn't like to pick who will go all the way. It will probably go right down to the wire."
QPR travel to Derby County on Monday evening.