Ruling for the first time on the controversial question of how much special assistance a public school district must make available to a handicapped pupil, the Supreme Court held yesterday that federal law requires school boards to provide some services for the handicapped, but not all those needed to "maximize" a student's learning potential.

The 6-to-3 decision, written by Justice William H. Rehnquist, said that under the federal Education for All Handicapped Children Act of 1975, Amy Rowley, an 11-year-old deaf girl, is not entitled to a free sign language interpreter as ordered by a lower court.

The family's attorney, Michael A. Chatoff, who is deaf and read the justices' questions in oral argument with the aid of a computer, described Amy as a bright child who had been progressing well in her classes by reading lips. But the interpreter was needed, he told the court, so Amy would have a chance to reach her full potential, the same as nonhandicapped students. The lower courts agreed and ordered the New York state school she attends to provide the interpreter.

The decision was the Supreme Court's first review of the act, which assures that states provide a "free appropriate public education" to students with disabilities. Gwen Gregory, deputy legal counsel for the National School Boards Association, whose members have been fighting lawsuits under the act, said the decision limits a board's duties and also limits the federal courts' ability to "second guess" local educational decisions.

Al Pimental, executive director of the National Association for the Deaf, said the ruling was "very negative" and accused the majority of "making the law, rather than interpreting it."

Nancy Rowley, Amy's mother, said yesterday at her home in Montrose, N.Y., that "it isn't fair. She was ready to be equal. She has the right to progress."

The case turned on the court's interpretation of what Congress meant by "free appropriate public education." Rehnquist said that in passing the 1975 law, Congress "sought primarily to make public education available to handicapped children. But in seeking to provide such access to public education, Congress did not impose upon the states any greater substantive educational standard than would be necessary to make such access meaningful."

He said Congress recognized it couldn't guarantee any particular educational outcome for the 4 million students served under the law. "Thus, the intent of the act was more to open the door of public education to handicapped children on appropriate terms than to guarantee any particular level of education once inside," he wrote.

States meet the act's requirements "by providing personalized instruction with sufficient support services to permit the child to benefit educationally from that instruction," Rehnquist added. There is no requirement in the law, he said, that the services provided "be sufficient to maximize each child's potential" with the opportunities provided other children.

The decision in Hendrick Hudson District Board of Education vs. Rowley also warned lower courts to "be careful to avoid imposing their view of preferable educational methods upon the states."

The act contains strict procedural protections for parents, which Rehnquist said showed that Congress meant "adequate compliance with prescribed procedures will in most cases assure much, if not all, of what Congress wished in the way of substantive content in an IEP individualized educational program ."

Chief Justice Warren E. Burger and Justices Lewis F. Powell Jr., John Paul Stevens, Harry A. Blackmun and Sandra Day O'Connor joined Rehnquist.

Blackmun said he felt the law did require equal opportunity for handicapped children, but that the school board in the Rowley case had tried to provide it.

Justice Byron R. White wrote a dissent, joined by William J. Brennan Jr. and Thurgood Marshall, in which they accused the majority of misreading the legislative history of the law. Providing Amy Rowley with some educational benefits is not enough, White argued. He said the majority seemed to be saying "a teacher with a loud voice" would be enough to satisfy the law's requirements.

Pat Wright of the Disability Rights Education and Defense Fund Inc. said the handicapped education law was drafted so strongly that the ruling "couldn't take away the rights of disabled school children and their parents." She said her group "is concerned the decision will be interpreted as a setback" so "we will be vigorously monitoring the actions of school districts and the Reagan administration."