Hii

For your question the answer is YES. Class 10th & class 12th marks matter f or getting a call from IIM . They first shortlists u on the behalf of your academics score's i.e. 10th, 12th & your graduation percentile and then call you for GD/PI round.

candidate must have at least 80+% in both 10th and 12th, and a 90+% score in std. 10th improves your chances of a shortlist.

Hope this helps.