Do students have a right to participate in school athletics?
Participation in school athletics is not a right, but a privilege, for students who attend the school. While rights to a public education is universal, school athletics are not considered a mandatory part of that education. They are instead considered an extracurricular, voluntary activity that students choose to do, placing them outside of the general school curriculum. Thus, it's not seen as a fundamental right of the student to be allowed to participate in these sort of activities.
While school athletics are shown to be a beneficial part of any school experience, and are highly encouraged, participation is often subject to various rules and regulations that students are required to meet in order to take advantage of them. For example, a student may be required to achieve a certain grade point average to enroll in extracurricular athletics. Should a student be forced to withdraw from an athletic program, or not be allowed to join in the first place, because they failed to meet such requirements, it's considered a denial of privilege, not a violation of that student's rights, and it is well within the legal rights of the school to enforce these rules.
However, schools are subject to anti-discrimination laws and administrators must treat students equally on the basis of race, gender, religion, disability, national origin, or any other protected status. Thus, while a school can set guidelines concerning who may participate in athletics, those rules apply to everyone and must not be in violation of civil rights or discrimination laws, unless there is a bona fide reason for the discriminatory rule.
If you have concerns that your school or school district is treating a student unfairly regarding athletics, it's in your best interests to consult with an attorney to determine if you have any legal options.