What are the parameters in the SIB1 that points on the CORESET for the schedule RAR?

Hi Experts.

What are the parameters in the SIB1 that points on the CORESET for the schedule RAR?

RAR resources are scheduled over DCI 1_0 scarmbled with RA-RNTI.

Thanks.

But my question is how the UE knows how to find the CORESET that holds this DCI.