A student's rights at a university disciplinary hearing will depend on the particular school involved. Schools have specific policies in terms of how cases would be addressed. It will also vary based on the nature of the offense. At a given school, it may have a certain process for an academic misconduct charge. It may have a certain process for a general disciplinary issue. It may have another process altogether yet for say Title IX sexual misconduct. Now a Title IX sexual misconduct is further complicated by the fact that schools are bound by federal law. Title IX is a federal civil rights law that's intended in part to prevent and address campus sexual misconduct, so the school has to meet those requirements if it receives federal educational funding.
That being said, the school policy will articulate the rights. It may be the right to call witnesses to present evidence on a person's behalf, to confront an accuser, to be more theoretical in nature. Students at a public university, for example, have due process rights under the constitution. Students at both a public and private university would have contractual rights. When they become a student and the school accepts them as a student, there's a contract between the parties, so there's multiple rights, multiple considerations involved. An experienced attorney advisor can help a student through the process, both to navigate and to understand their rights and to maximize the prospect of success.