Christianity

Both of these are premier institutions for arts and science courses. They are widely preferred by many students as they are top ranked ones.
But when we compare MCC and Ethiraj, MCC is better.
The college is affiliated to the University of Madras but functions as an autonomous institution (deemed university) from its campus in Tambaram, Chennai. MCC has several civil servants, administrators, educators, business people and political leaders, around the world among its professors and alumni. It is accredited by NAAC. It is Ranked 6 for Arts by The Week and Ranked 7 for science by India Today.
The student reviews are also really good which is one of the important criteria for the selection of a good college.

Both Loyola College and Women's Christian College (WCC) are good for humanities courses.
But when we compare these two, Loyola College is better. Loyola beats WCC in the following aspects:
Loyola College is the only college in the state capital Chennai with "A+" accreditation from NAAC. According to NIRF rankings 2017, Loyola is at the 2nd position among all the colleges in India. For which you may refer:
https://www.nirfindia.org/CollegeRanking.html
The India Today magazine in 2005, 2006, 2007, 2008, and 2009 ranked Loyola No. 1 in India for science degrees
The Department of Scientific and Industrial Research has recognised Loyola College as a Scientific and Industrial Research Organisation, the highest research honor for an Arts and Science College.
Not only the rankings, but also the infrastructure and the alumni of the institution make it a better institution to study.