Along with the GPA requirement, you also need to finish the following to have your TAG agreement to UCI approved:
- Have 30 semester units / 45 quarter units completed prior to submitting the TAG
- Complete your 1st UC-English requirement by the summer prior to applying for the TAG
- Complete your UC-Math requirement by the summer prior to applying for the TAG
- Submit the application by the September 30th deadline
For CS, I also think you have to have at least one CS approved calculus course and one computer science course completed or in progress or else they will deny you for not being able to finish the major prerequisites otherwise.
Sources: http://admission.universityofcalifornia.edu/counselors/files/tag-matrix.pdf & http://admissions.uci.edu/applicants/transfer_prep/prep_ics.html
- Note that these are for this academic year, and might change (unlikely) for next year.