GIBS is pretty chill and flexible with entrance exams. They accept almost all the common ones.
If you've written CAT, XAT, MAT, CMAT, GMAT, ATMA or even State CET, you're good to apply at GIBS.
Basically, any decent management entrance score works, and after that they focus more on your GD–PI performance, attitude, and overall profile.
Super simple process, nothing complicated.