To be honest, your 10th and 12th marks may not favour you. But your Graduation aggregate is really fantastic. When the IIMs shortlist candidates for WAT, they consider factors like your Academic profile, your CAT score, diversity factor, etc.

Few IIMs also consider Work experience. Now 71% in 10th and 61% in 12th, you will not gain much points on the rating scale. With 95% in Graduation, you might get 8-9 points. But with your 10th and 12th marks, you may get 4-5 points on the rating scale. And considering these 3 scores, your points might be between 12-14. Which means when IIMs shortlist Candidates for the next round based on your Category and all these factors, you might lag a little. But if you score 95 percentile in CAT, you may have it to your advantage.

If you don't have any work experience before, you can join a job, your work experience will show up and it will add few more points to your profile. Inspite of all this if you get a call from an of the IIMs with this current profile, nothing better than that.