With 93.1/74/92.5 in 10, 12, UG with no work experience, how much percentile can get me SPJIMR, NMIMS, and baby IIM like Shillong?

Having no work experience is not the main barrier to get into B schools. Your 10th and UG marks are very good and 12th marks are decent, however, I want to make it clear that IIM Shillong is not among the baby IIMs or the new generation iims. 

It is far better than new iims and making place among BLACKI. SPJIMR accepts CAT score for its admission and you will be requiring above 94 percentile for open category. NMIMS accept SNAP exam score. And for IIM shillong 95+ percentile is required.