Redknapp, who memorably led Portsmouth to survival in 2006, masterminded a goalless draw with Sunderland in his first game in charge on Wednesday, leaving the R’s eight points behind 17th-placed Aston Villa.
QPR face Paul Lambert’s side in a must-win game at Loftus Road on Saturday, and Redknapp admitted his side realistically needed 30 points from their 24 remaining games.
“It’s top form [10 wins from 24 games],” said Redknapp.
“You’re talking top six or seven form, that’s what we’ve got to show now. It’s like a handicap.
“We’ve given a points start to everyone so we’ve got to play catch up. We’re not kidding ourselves, it’s a difficult task but not impossible.
“I remember going to Birmingham and getting beaten 5-0. There were four teams adrift at the time and they beat us 5-0 at St Andrews and it could have been 10, it was my first or second game back.
“I looked at their team, a fantastic, strong side with Chris Sutton and Emile Heskey up front, full of quality players.
“After that night, I drove away thinking how can we finish above them, but we did. We had a little run and it turned.”
Redknapp’s ranks guiding Bournemouth into the old Second Division, keeping Portsmouth in the top flight in 2006, and taking Tottenham into the Champions League for the first time among his best achievements in a 29-year managerial career.
However, the new Hoops boss, who has already converted his grandchildren into QPR supporters, admitted completing the rescue mission at Loftus Road would be one of his greatest feats.
“If we could pull this off, it would be a great feeling to do it,” he added. “There would be a lot of satisfaction if I could play a part in keeping us up now. That’s the ambition.
“Listen, I can only do my best, that’s all you can do in this life. If it works – great, if it doesn’t – I tried.
“I could have stayed at home and played golf or waited for another job to come along, which it would have done.
“Once I met the people at QPR, they were fantastic people and I’m here to give it my best.”