Education Secretary William J. Bennett told state school superintendents yesterday that they must continue to provide remedial instruction to needy children who attend religious schools this fall, even though a recent Supreme Court decision means they will have to do so on "neutral" territory.

At the same time, Bennett told the state school chiefs that he still opposes the Supreme Court's July 1 decision, and promised to help any locality that decides to go to court to delay having to comply with it.

"This department will support local and state agencies in litigation who have good grounds for requesting necessary delays in implementing the Supreme Court's decision," Bennett wrote school officials.

A department spokesman, Marie Robinson, said department support could include financial help, but such decisions "will be determined on a case-by-case basis."

The Supreme Court ruled in a New York case that federal money could not be spent in religious schools under Title I -- later called Chapter I -- of the Elementary and Secondary Education Act passed in 1965. That program provides federal aid to "educationally deprived" children in poor neighborhoods, and Congress specifically said the money must go to children in both public and private schools.

The city and state of New York went to court Wednesday seeking a year's delay in complying with the high court decision. Last week, a federal judge in Missouri denied a similar request by officials there, telling them to get a new plan in place when school opens.

About 183,000 children in private and religious schools across the country receive remedial instruction under the program, mostly in urban school districts. Many of those districts have been in a state of confusion since the Supreme Court ruling, and have been waiting for guidance from Bennett.

Bennett said students getting Title I aid could be bused to public schools for the classes, with transit costs taken out of program funds.

Samuel B. Husk, executive director of the Council of Great City Schools, said such an arrangement could mean "fewer children would be served," since "most districts now have zero for administrative expenses" under the program. Husk said some religious schools may decide to park a trailer on the street outside school buildings to provide a neutral location.

Bennett said the high court's ruling added "greater urgency" to the idea of a voucher plan that would give money for remedial instruction directly to parents, They would be able to send children to the public or private school of their choice, even a religious school. Husk said the voucher plan would just open "up another case which is going to be easier for the courts to decide."