Is your GPA unweighted or weighted? Test scores? and can you list your EC’s. No way of chancing you without all this important information.
Here are the UC requirements for International applicants:
http://admission.universityofcalifornia.edu/international/applying-for-admission/index.html
UC’s review your application based on GPA/Test Scores/HS course rigor/Essays and EC’s.
Here is average GPA/Test score data from last year for admitted UC’s applicants for UCLA/UCB:
CAMPUS/ AVG UC GPA/ AVG ACT/AVG SAT TOTAL/ AVG SAT M+CR
UCB: 4.19 / 31 / 2094 /1396
UCLA: 4.18/ 31/2064/ 1377
To be a competitive applicant, you want to be at or above the average. The more competitive the major, the higher the stats.