What is roll of extra curriculam activity in selection process of b school?
IIMs use a composite score allocating different weightages to parameters like CAT score, academics, work experience, diversity etc. for shortlisting candidates for WAT/PI. These weightages vary from institute to institute.
Based on the performance of WAT/PI, a final score is computed, depending on which admission offers are rolled out.
Though the selection process has zilch weightage on extra-curricular activities, interview panels value it a lot. Extra-curriculars can also be used to drive interviews towards your interests and impress the panel. In short, it can add to your PI score and thereby, your final score. Good luck!