The Brazilian goalkeeper is desperate for regular first-team football ahead of the World Cup next summer.
Cesar is currently behind Robert Green in the pecking order at QPR. Cesar signed a four-year contract when he joined QPR in 2012, but he has recently been strongly linked with a move to Manchester City.
"We wouldn't stand in Julio's way and we aren't asking a fee for him," Redknapp said, quoted by the Fulham Chronicle.
"He needs to play and he could play anywhere for any team. He's just been unlucky.
"Rob's been fantastic and I can't take him out of the team.
"However, Julio's a great guy, and he needs to play soon, so he can play in the World Cup."