Plagiarism is a serious allegation. It's especially serious if you're at the graduate school level and you're accused of such misconduct. Even undergraduate students are held to a high level of accountability. As a graduate student, the expectation is higher yet. What's something that can result in a lesser sanction if a student is found responsible at the undergraduate level can result in a more severe outcome such as suspension or expulsion at the graduate school level?
Something that you need to bear in mind if you're accused. Because plagiarism is a nuance charged in the sense of whether a person actually committed plagiarism or not, and how the school came to make that allegation. Was it because they're using a plagiarism checker like SafeAssign or a similar program and it turned up an erroneous result and now you're being falsely accused? Was it because you failed to properly cite maybe because of a misunderstanding or because of a cultural difference, for example, if you're an international student?
There's many nuances and considerations in terms of whether a school is even within its rights in making the allegation or say if a student were to be responsible or culpable under the school's policies. It is a very serious allegation, you need to have an experienced attorney advisor help you understand and protect your rights, and to help you navigate the process. They should be involved as early as possible if you're accused of plagiarism at the graduate school level.