One of my friends graduated from Loyola College and here are some of the things I got to know from him. This information might answer your question. 

• Firstly, have a community certificate and good scores.
• Secondly, it depends on the kind of program you're looking for. For instance, VISCOM is the only program that has an entrance exam and personal interview.
• All other programs are on a merit basis where the cut-off varies from department to department. Only B.Com and BBA departments have strict cut-offs. 
• The rest of the departments should accept average applicants provided you have a caste certificate.
• You might think it is merit, but no. You need to be a catholic, that's the first requirement. If you are a Roman Catholic that's an added advantage.

They prefer Christians though they do admit students from other belief systems or religions that only account for around 10 to 20% of admission where they consider your scoring.