UCI only accepts Junior level transfers with 60 semester/90 quarter units. Since he has already enrolled in another University, he will be considered a Transfer and cannot apply as a Freshman.
Many students have difficulty the first semester or two in college so I personally would make him complete the first year at the college he is now and then re-evaluate his options.
For UCI, he could withdraw at his current university and attend a Community College for the next 1 1/2 to 2 years and then transfer. Not sure if you are in-state, but for UCI priority is given to in-state CA CC transfers and depending upon major he could TAG (Transfer Guarantee admission) if he meets the required courses and required GPA.
Edited: Wanted to add that UCI does not accept Winter/Spring Quarter admits as Freshman or Transfers.