Oracle 11g Release 2

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

with t(id, campus, credit_hr) as (
    select 1, 'MIC',     3 from dual union all
    select 1, 'Warrens', 4 from dual union all
    select 1, 'Online',  3 from dual union all
    select 1, 'Online',  3 from dual union all
    select 2, 'MIC',     5 from dual union all
    select 2, 'Warrens', 3 from dual union all
    select 2, 'Online',  6 from dual union all
    select 3, 'Online',  3 from dual union all
    select 3, 'Online',  3 from dual union all
    select 3, 'West',    2 from dual union all
    select 4, 'Warrens', 3 from dual union all
    select 4, 'MIC',     3 from dual union all
    select 4, 'West',    7 from dual union all
    select 5, 'Online',  3 from dual union all
    select 5, 'West',    3 from dual union all
    select 5, 'East',    3 from dual )
select * 
  from (
    select a.*, row_number() over (partition by id order by major, sm desc) rn
      from (
        select id, campus, 
               case when campus in ('MIC', 'Warrens') then 1 else 2 end major, 
               sum(credit_hr) over (partition by id, campus) sm
          from t) a)
  where rn = 1

ID	CAMPUS	MAJOR	SM	RN
1	Warrens	1	4	1
2	MIC	1	5	1
3	Online	2	6	1
4	MIC	1	3	1
5	East	2	3	1