What are my chances of getting into CSUs if i have a 2.8 GPA and 21 on ACT? Which CSUs can i get into
Your eligibility index is 770 which qualifies you to apply to a CSU (minimum EI is 694). I would look at the non-impacted campuses such as Monterey Bay, Channel Islands, East Bay, Stanislaus, San Marcos, Humboldt and Fresno to name a few. Check the common dataset for each campus to see where your stats fit in.
https://www.calstate.edu/sas/documents/impactedprogramsmatrix.pdf
Good luck.