Bain is hiring less than other MBB companies globally, thus their application filtering process may be even more strict in some countries. That's why you should be either highly qualified or being well qualified but having a referral.
Pls find more information regarding the referral here:
As for the general criteria, they mainly look at:
- Education and GPA - they are looking mostly for top schools and best score
- Work experience - if you have a lot of relevant experience, education is less important. Both brand and your role in the company are important
You can also increase your chances by having additional qualifications: tests, technical skills, extracurricular activities, achievements, etc.