UC accepted but low grades

I have been accepted into UCSD and UCD. However, I am still giving my Indian XII exams. I think I may not meet the qualifications listed on this page - http://admission.universityofcalifornia.edu/international/applying-for-admission/freshman-requirements-country/#india.
It states that I must have more than an average of 70 and every score to be more than 60. I will probably meet the average requirement but I might get a score lower than 60 on my chem exam (my major is Physics). How likely are they to cancel my offer if this happens, will my giving the APs and achieving 3+ in that help?

Thanks

Each UC is different, but you do not meet the requirements listed, contact the schools and see what kind of options are offered.