Contracts with State education agencies or public school districts receiving funds must provide educational opportunities to all Indian children within that school district on the same terms and under the same conditions that apply to all other students as long as it will not affect the rights of eligible Indian children to receive benefits from the supplemental programs. Public school districts receiving funds must ensure that Indian children receive all aid from the State, and proper sources other than the Johnson-O'Malley contract, which other schools in the district and other school districts similarly situated in the State are entitled to receive. In no instance may there be discrimination against Indians or the schools enrolling Indians.