Chavez's decision to not to renew the channel's free-to-air licence has prompted international condemnation and several demonstrations.
A defence ministry official said he had not seen the court decision while an RCTV lawyer declined to comment.
The decision came hours after a convoy of troop carriers, motorcycles and armoured anti-riot vehicles patrolled the highways of Caracas to deter disturbances by opposition supporters.
Chavez said on Friday that Venezuela's government was ready for any attack by "the oligarchy" - a pro-US elite which Chavez says RCTV epitomises.
|Hundreds of people protested in Caracas against the government closure of RCTV [AFP]|
Earlier on Friday, hundreds of people protested in Venezuela's capital against the imminent government move against RCTV.
He said: "We will be on alert, we are always on alert. Whatever flares up, we will snuff it out."
'No to closing'
Hundreds of students shouted "No to the closing!" as they gathered on Friday for a march to Venezolana de Television, the main state-run channel.
The demonstration came after a protest in the capital last Saturday, which thousands of people attended.
"People have to realize that we have a totalitarian president," said Maria Alecia Klemprer, a 25-year-old university student at Friday's rally.
"Minority groups cannot go against the will of the majority of the Venezuelan people to create uncertainty in the case of RCTV's licence"
Raul Baduel, Venezuela's Defence Minister
Hundreds of police and national guard troops have been dispatched across Caracas to discourage expected demonstrations on Sunday, when RCTV goes off the air.
Venezuela's government says opposition demonstrators are pursuing a "destabilisation campaign" as RCTV loses its licence.
Raul Baduel, Venezuela's defence minister, said on Friday that "minority groups cannot go against the will of the majority of the Venezuelan people to create uncertainty in the case of RCTV's licence".
The US senate foreign relations committee passed a resolution on Thursday against the "transgression of freedom of thought and expression" in Venezuela.
Human Rights Watch and Reporters Without Borders have also condemned the move against RCTV.
RCTV has operated since 1953 and has consistently led viewing figures in Venezuela.