Rangers enter Sunday's clash with Liverpool at Loftus Road six points adrift of safety following successive defeats by Newcastle and West Brom and Redknapp accepts they must strengthen in the transfer window.
Demba Ba, Brede Hangeland and Robbie Keane are among Redknapp's targets with the QPR boss insisting any new signing must bring something to their survival bid.
"If we can get one or two in, we'll give ourselves a chance. That's what I'm looking at," said Redknapp, who denied having made an approach for Hangeland.
"If I can't bring in people who I think can do the job for us, then I won't bother. There's no point signing players for the sake of it.
"I've got to sign people in the right positions who can help us. If we can't do that, we may as well sit tight and see what happens."
The future of Jose Bosingwa remains uncertain after the Portuguese right-back refused to sit on the bench against Fulham on December 15, resulting in him being dropped altogether and a £130,000 fine.
"We'll have to look at that and see how we're going in January," said Redknapp.
Redknapp added: "I can't look to get rid of anyone - I had to pull in a kid who had been on loan at Yeovil on the bench against West Brom.
"We're certainly not over-loaded. Out of the 25 we have long-term injuries. I won't shift people out unless I get some in."
Redknapp had an immediate impact when he was appointed Tottenham manager in October 2008, lifting a team that had secured only two points after eight games out of the relegation zone within two weeks.
Despite having steadied the ship at Loftus Road, his impact has been less marked with six points in six games leaving the club in a precarious position.
"I didn't expect it to happen quickly here. Spurs and QPR are two different clubs. How Spurs were in that position in the first place I'll never know," Redknapp said.
"There was a long way to go there, only eight games had gone and they had a fantastic squad. Here we'd gone 13 games without a win. It was always going to be much harder.
"No one has a magic wand to start winning games. It's not just going to happen, it's difficult. It's been like I've expected it to be."