Assignment of pupils to schools – Non-resident pupils – Tuition – Race discrimination. To assign pupils to the several schools in the district; to admit non-resident pupils when it can be done without prejudice to the rights of resident pupils and provide them with any services of the school including transportation; to fix the rates of tuition in accordance with Section 10-20.12a, and to collect and pay the same to the treasurer for the use of the district; but no pupil shall be excluded from or segregated in any such school on account of his color, race, sex, or nationality. Nothing herein shall be construed to permit or empower the State Board of Education to order, mandate or require busing or other transportation of pupils for the purpose of achieving racial balance in any school.