SIP and SIR?

So i was accepted by another UC, but got waitlisted at UCI.
UCI is my first choice, can i submit an statement of intent to register at that UC and still submit an SIP to UCI?

Yes

So what willl happen if i got admitted to UCI? It said i can only submit one SIR, but i will have submitted one to another uc :confused:

you have to cancel your SIR to that school (by mail?) and submit another SIR to Irvine!