I have got 77% in 10th, 67% in 12th(commerce without maths) Bihar board & 62% in B.Com-1 from Patna University. Can I get a call from IIMs?

Hi, 10th score, higher secondary score doesn't matters and in B.Com you have scored above 60% all matters is how much you score in CAT exam that totally depends on call for IIMs and the score should be above 90+.

Since you fulfil the basic criteria of 60% in graduation, you need not worry about the 10th and 12th score. All you need to concentrate on now is you CAT scores, which should be fairly good- basically, above 90 to get the call.