Given that your GPA is below both schools' averages and your SAT score is slightly below UNC and UVA's averages, your chances are further decreased. However, there are a number of other factors that UNC and UVA consider in the admissions process, such as extracurricular activities, letters of recommendation, and personal statement. If your application is particularly strong in these other areas, you may still have a chance of admission.
Additionally, UNC and UVA both offer a "dual admission" program, which allows students to be admitted to one school but take classes at both. This can be a good option for students who are unsure of which school they want to attend or who want to explore different academic options.