From the RIT's Undergraduate Bulletin:
Rochester Area College Course Work Agreement
RIT is a member of the Rochester Area College (RAC) consortium. These colleges have instituted a cooperative program, which provides undergraduate students the opportunity to register at a member college without additional tuition charges.
The following Rochester area institutions of higher education are members of the consortium members:
Colgate Rochester Divinity School
Empire State College
Finger Lakes Community College
Genesee Community College
Hobart & William Smith Colleges
Monroe Community College
Roberts Wesleyan College
Rochester Institute of Technology
St. Bernard’s Institute
St. John Fisher College
State University of New York at Alfred
State University of New York at Brockport
State University of New York at Geneseo
University of Rochester
Students must meet the following criteria in order to enroll as an intercollegiate student:
The requested course is not available at the home school.
The student is a full-time (12 credit hours or more) matriculated undergraduate student at their home school throughout the duration of the requested course.
The course is applicable toward the student’s undergraduate degree program.
Registration for the course is on a space available basis.
If the requested course causes the student to assume a course overload, the additional charges will be based on the current rates of the home school during the semester or quarter in which the registration takes place.
Students enrolled at area colleges may register for two courses at RIT.
The program is not available in the summer.
Additional criteria is outline on the intercollegiate registration form available at the Registrar’s Office. Academic Enrichment
And since there exists on UR's Financial Aid Office website a form petitioning to maintain a student's financial aid at UR while attending a class elsewhere, I would say that UR actively participates in the consortium and allows cross-enrollment.