As I understand umich does not offer direct admission to major. If so, after being admitted to umich, how does one get into CS major? Is there a limit on how many students can enroll into CS major? If so, given the high demand for CS major, who gets in and who doesn’t?
Here is what UM has to say:
https://admissions.umich.edu/academics-majors/majors-degrees
So, yes, you DO have to apply to the particular college that houses your major, which for CS can be either LSA or Engineering. There are certain majors for which you may not apply until sophomore year, but CS is not one of them.
You have to apply to enter in a division. CS can be in either LSA or CoE.
After enrolling in LSA or CoE:
LSA CS requires 2.5 GPA in prerequisite courses, all of which must be completed with C or higher grade: https://cse.engin.umich.edu/wp-content/uploads/sites/3/2020/06/cslsa_guide_fall_2019.pdf
CoE CS requires 2.0 GPA overall and completion of prerequisite courses: https://cse.engin.umich.edu/wp-content/uploads/sites/3/2020/06/cse_guide_fall_2019.pdf