Croatia midfielder Modric has been in scintillating form for Spurs this season, playing a key role in their run to the Champions League quarter-finals on their debut in the competition.
The 25-year-old has been linked with a host of rival clubs, including Chelsea, Juventus and Inter Milan.
But speaking to Croatian newspaper Sportske Novosti, Redknapp said: "I wouldn't want to sell him for ?100million, not even for a billion.
"He's the hub of the team."
Source: PA
Source: PA