What are the differences between ci6124 vs h6677 vs k6125?

I really don't know.
Why are there 3 very similar graduate courses?
In this case, it all boils down to the preferences/styles of individual instructors.

You should sit in both courses to get a feel of which style is more suitable to you.

For instance, the combined course of h6677/k6125 is taught by professor Christopher Khoo, a well known data mining expert.

Professor Khoo's course includes regular lab sessions, which means you get a chance to play with some data-mining software.

My course has 2 planned lab sessions in lieu of lectures. You will be using SAS Enterprise Miner in the CAIS (N4-b3c-14) lab.

All 3 courses use the same textbook (tan/steinbach/kumar), coincidentally. My slides are largely based on the textbook material.

My personal preference is to stress more on the theoretical foundations and mathematics whenever it makes sense to show the equations.

Prerequisites: College Calculus, College Probability