Guess who is coming out of the Rose Garden?

President Carter, who vowed not to campaign until the American hostages in Iran are released and who for almost six months has imposed a near-total travel ban on himself, abruptly changed those ground rules yesterday.

In the aftermath of the unsuccessful attempt to rescue the hostages last week, Carter told a group of civic leaders at the White House yesterday that he plans to resume "a limited travel schedule, including some campaigning if I choose."

The change in plans comes after Carter's greatest risk as president ended in failure and the deaths of eight American servicemen in the Iranian desert, and while the president remains in a battle for the Democratic presidential nomination with Sen. Edward M. Kennedy (D-Mass.).

But presidential aides, asserting that Carter already has the nomination locked up, said politics was not the primary reason for the change in tactics.

Rather, they said, Carter has concluded that the rescue attempt amply demonstrated the United States' "seriousness of intent" over the hostage issue, and that he could now resume travel and campaigning without sending Iranian authorities "the wrong signal" about his determination to free the hostages.

Kennedy immediately challenged the president to a debate, but was turned down before he issued the challenge. "Any place in this country, anytime," Kennedy said.

In a press conference in Indianapolis, Kennedy said the president's decision "to come out of the Rose Garden and face the American people . . . is a victory for the process and the political system."

He mocked Carter's suggestion that presidential campaigning is now possible because the problems are "manageable."

"Is an inflation rate of 18 percent manageable for the American people?" he asked. "Are our interest rates of 18 percent manageable for young people who would like to buy a home?"

Kennedy said the White House announcement reflects "basically a political judgment." He said the president decided to campaign because Kennedy had won, usually narrowly, a number of contests with Carter in recent weeks.

White House officials said later that no trips for the president are now scheduled but some will be arranged soon.

White House press secretary Jody Powell also said that, while Carter will campaign, he will not debate Kennedy.

"He sees no purpose to be gained by it," Powell said.

In November, two days after the hostages were taken and at a time when he trailed Kennedy in public opinion polls, the president agreed to debate Kennedy in Des Moines before the January Iowa Democratic caucuses, the first step in the race for the nomination.

But seven weeks later, with his public support rising amid the drama of the hostage crisis, Carter pulled out of the Iowa debate, saying the Iran situation and the Soviet invasion of Afghanistan required him to "forgo personal appearances . . . which are exclusively part of a partisan political campaign."

Powell said that, if he wins the Democratic nomination, the president will debate his Republican opponent in the fall.

White House officials indicated little concern over the criticism they expect to be leveled at Carter for abruptly ending the self-imposed White House isolation that apparently benefited him at least in the early stages of his battle with Kennedy.

"I'm sure he made the decision with the full knowledge that he'd get beat around the head and ears," an official said.

But a presidential aide also said one factor in Carter's decision was what he took to be indications that Kennedy, who Tuesday visited the five servicemen injured in the rescue attempt in San Antonio, is "toying with the idea of trying to make this [the rescue attempt] an issue."

"His reaction was that he wants to be in a position so he can respond and take him head-on" in that event, the aide said.

The president's announcement came in a highly staged atmosphere in response to an obviously planted question from Charles Manatt, chairman of the Democratic National Committee's National Finance Council.

In light of the unsuccessful rescue attempt, Manatt said he wondered whether the American people might now get to see their president in person.

"Yes," Carter responded as the East Room quickly filled with applause.

"It's been a long time," he continued. I have stayed in the White House under extraordinary circumstances. But times change and a lot of the responsibilities that have been on my shoulders have been alleviated."

The president said he is determined to keep the plight of the hostages "vividly in the minds of the American people." But tracing the steps he has taken to deal with the Iran crisis and other foreign and domestic issues, he said these problems have become "manageable enough" to allow him to resume a limited travel schedule.

White House officials said Carter is expected to confine his initial travel to relatively short, one-day trips and to be out of Washington no more than one or two days a week.

One purpose of these appearances, the officials said, will be to focus some public attention on issues other than Iran. They mentioned economic issues and the question of registration for the draft, a subject on which Carter has been virtually silent since proposing it in his State of the Union message in January.

Except for weekend trips to Camp David and a visit to the injured servicemen in San Antonio Monday, the president has not been out of Washington since Oct. 29.