The Miami relatives of 6-year-old Elian Gonzalez won a surprising legal victory here today when a state court judge ruled that she has jurisdiction over the boy's custody case, setting up a possible showdown with the federal government over its order that the child be returned to his father in Cuba by Friday.

In her ruling, Miami-Dade Circuit Court Judge Rosa Rodriguez said that Elian's return to the communist country could cause the child "imminent harm" and scheduled a full hearing on the case for March 6. She issued a temporary protective order for the child, keeping him with his Miami relatives, and indicated she will ask Elian's father, Juan Miguel Gonzalez, to come here from his home in Cardenas, Cuba, to attend the hearing.

The legal team representing Elian's Miami relatives was elated by the ruling.

"Today's order of the court . . . will permit Elian his day in court," said Spencer Eig, one of the attorneys, speaking outside the downtown courthouse. "It's up to the state of Florida now to determine what is in his best interests."

Immigration and Naturalization Service lawyers in Washington were studying the Florida court decision this evening to determine "what effect, if any, it has on our ruling," an INS spokeswoman said. Last week, INS and Justice Department sources had said that state court decisions would have no impact on their ruling that only Elian's father has the right to speak for him on immigration matters.

Elian's great-uncle, Lazaro Gonzalez, had filed the emergency petition for temporary custody in the state court Friday in an attempt to forestall the boy's return to his father, ordered last week by the INS. Elian's fate has been undecided since Thanksgiving Day, when he was found off the south Florida coast, one of three survivors of a shipwreck that took the life of his mother and nine others as they attempted to reach the United States.

The development today marked the first legal protection that Elian has received from a state court and threw into further confusion the question of who has final jurisdiction over the boy's future.

Attorneys for Elian's relatives in Miami were coy about their next move. Asked whether the relatives plan to file a petition in federal court, as they had threatened, Eig hedged. "We are going to take a deep breath," he said, "and figure out what we are going to do."

In their petition to Rodriguez, Eig and the others had argued that the father could not speak freely in Cuba, and was being forced to "only express the mandates of the government."

In Washington, officials appeared unsure how to proceed in the face of the onslaught from Miami and the rejection of the original INS appeal for all of Elian's family members to "cooperate" in returning the boy to his father.

They acknowledged that the politics of the situation may make the INS position that the boy must be returned by this Friday difficult to maintain, even if it argues that the current challenges to the ruling are immaterial.

One senior official last week said the "worst case scenario" was for federal marshals to physically remove Elian from Miami and no one in Washington seems prepared to do that. "We've never had any intention of taking the child into federal custody and removing him," another official said today.

At least one child custody expert was surprised by the Rodriguez ruling and expressed shock that she would delay the evidentiary hearing for so long. Bernard Perlmutter, who heads the Children and Youth Law Clinic at the University of Miami, said there is "a high burden to satisfy under such proceedings" and called the March 6 date "ludicrous and ill-serving of Elian's interests."

From his home in Cuba, Juan Miguel Gonzalez, a hotel worker, reportedly has said he has no intention of traveling to the United States.

Protest leaders from Miami's large Cuban American exile community said they would respect the decision of the courts, even if it means the boy eventually will have to return to Cuba. On Saturday, they postponed further protests, citing the petition before Rodriguez and a subpoena issued late Friday by Rep. Dan Burton (R-Ind.), that also sought to delay the boy's departure.

"This is a temporary victory but it is what we have wanted all along," said Ramon Saul Sanchez, leader of the anti-Castro Democracy Movement, at the courthouse news conference.

Meanwhile today, the war of rhetoric continued.

Speaking on NBC's "Today" show, Vice President Gore more emphatically distanced himself from the Clinton administration policy on the case. Both President Clinton and Attorney General Janet Reno have refused to reverse the INS decision.

"I'd like to see the dispute adjudicated in our courts, where traditionally, questions like what is best for this child are decided," Gore said. "This child's mother died in an effort to give her child freedom."

Asked earlier today if he was troubled by Gore's comment, Clinton said, "Well, anybody is free to express their opinion about this. . . . What I have successfully done, I think, is to make sure we got through the decision without it becoming overly politicized. . . . I think the INS tried to do what was right by the child."

Pressley reported from Miami; DeYoung from Washington. Special correspondent Catharine Skipp in Miami contributed to this report.