The Supreme Court, in a significant victory for civil rights groups, said yesterday that broad affirmative-action plans that include hiring goals are constitutionally permissible so long as they are carefully tailored to remedy past discrimination.

The justices, acting in the first of three major affirmative-action or "reverse discrimination" cases at the court this term, appeared to signal their rejection of the Reagan administration's position that such broad plans are inherently unconstitutional because they harm "innocent whites" while benefiting minorities who were not actual victims of discrimination.

At issue was a voluntary arrangement between a teachers union in Jackson, Mich., and the local school board to lay off white teachers before laying off blacks with less seniority in order to preserve minority hiring gains. The court struck down the affirmative-action arrangement.

The court said the Jackson plan did not pass muster because officials there failed to provide adequate evidence of past discrimination in the school system.

The ruling's importance, however, stemmed from the language used by individual justices in explaining their positions. The court was splintered in the case, as it has generally been in affirmative-action controversies, with no five-member majority joining any single opinion.

But civil rights lawyers agreed with Justice Sandra Day O'Connor, a pivotal vote in the case, that the language of the opinions showed a strong majority in favor of affirmative action in general and in agreement on "certain core principles."

She said the court clearly agreed that public employers could have affirmative-action plans to remedy past discrimination so long as those plans do not "unnecessarily trammel the rights" of "innocent individuals."

In addition, O'Connor said a majority also "forged a degree of unanimity" on the view that such plans "need not be limited to . . . remedying . . . specific instances of identified discrimination," as the Reagan administration has contended.

Those words, if adhered to by a full majority in the future, were seen as extremely significant by court observers. Broad hiring goals or quotas tend to provide job opportunities for whole classes of minorities, whether individually victimized or not. A requirement that affirmative-action plans benefit only specific victims would doom virtually every large-scale program of hiring goals. Until yesterday, the views of a court majority on this question were unknown.

Justice Lewis F. Powell Jr., writing for a plurality in Wygant v. Jackson Board of Education, said the Jackson plan was invalid because Jackson officials did not adequately justify it with careful findings of past discrimination and because layoffs were too drastic to be used in affirmative-action plans.

Such plans, he said, cannot be justified by generalized claims of "societal discrimination," because that is too "amorphous a basis" for allowing affirmative-action plans.

There must be "convincing evidence" of discrimination by a government unit before affirmative-action plans are appropriate, Powell said, and the Jackson school board did not provide it in this case.

But "other, less intrusive means of accomplishing similar purposes -- such as the adoption of hiring goals -- are available," Powell said, implicitly endorsing the use of such goals in proper circumstances.

"As part of this nation's dedication to eradicating racial discrimination," he said, "innocent persons may be called upon to bear some of the burden of the remedy."

"In cases involving valid hiring goals," he said, "the burden to be borne by innocent individuals is diffused to a considerable extent among society generally." Powell said layoffs, in contrast, "impose the entire burden of achieving racial equality on particular individuals."

Powell was joined in full by Chief Justice Warren E. Burger and Justice William H. Rehnquist. Justice Byron R. White concurred. O'Connor joined most of the ruling, but apparently disagreed that layoffs would never be permissible under an affirmative-action plan.

O'Connor also concluded that public employers may undertake affirmative-action plans involving hiring goals without any court or other findings that they discriminated in the past. She said cities and states should be prepared, if challenged, to justify their actions in court, however.

Justice Thurgood Marshall, writing in dissent for himself and Justices William J. Brennan Jr. and Harry A. Blackmun on the narrower question of the Jackson plan, said the plurality opinion would "nullify years of negotiation designed to solve serious educational problems in the schools of Jackson, Mich."

Justice John Paul Stevens, also in dissent, said he felt that the school board plan served a "valid public purpose" and was adopted with fair procedures.

Civil rights groups said the opinions seemed to show a much broader agreement among the justices on the propriety of affirmative action.

Several civil rights lawyers expressed cautious optimism that they would win the two remaining cases involving Cleveland firefighters and New York sheetmetal workers. One attorney, E. Richard Larson of the American Civil Liberties Union, confidently predicted after yesterday's ruling that "we win" in those cases "if O'Connor is to be read literally."

Barry Goldstein, an attorney with the NAACP Legal Defense and Educational Fund, Inc., said "affirmative action survives" under the ruling. The Jackson case was unusual, he said, because very few plans involve layoffs and, unlike Jackson's, most plans were developed after specific findings in court of prior discrimination.

Justice Department spokesman Terry Eastland said the language in the various opinions was "opaque enough" to be interpreted in any number of ways, and said the department did not necessarily see the court as rejecting the department's views. The white teachers' claims "have been vindicated," Eastland said, with the high court's rejection of broad "societal discrimination" to justify specific affirmative-action plans.

The court is expected to rule by July in the remaining affirmative-action cases.