There seems to be a lot of confusion about how ISB sends out admits, WLs and Regret. As far as I understand, this is what happens.
When you apply, ISB takes your 10th, 12th, UG, GMAT scores and rates you - Ex. 3/5 for 10th, 2/5 for 12th and 6/10 for UG and 17/20 for GMAT/GRE
=> Score = 28/40
AdCom/Profs evaluate your Essays/LoR and give you a score => Ex. 15/20
Work Exp score => Ex. 12/20 {I believe there is an upper limit for Work Exp, i.e., you will get the same score even if you have 10 year exp or 8 years}
Cumulative Score = 55/80
At the start of the Season (before R1 interviews), they declare a Cutoff for shortlisting - Say 40/80 - If you get >40, they call you for interview irrespective of the Round you apply for.
Interview Score = (Say) 15/20
Final Cumulative Score = 70/100
Again at the start of the Season (after R1 interviews), they declare a Cutoff for admission and WL - Say 65/100 and 60/100 respectively. This remains same irrespective of the Round.
If your final score > 65, they give you an admit within a week or two.
If you score in the range of 60-65, then, they waitlist you after interviews for that particular Round are finished. WL movement happens after the entire cycle is finished.
If you score <60, they send out regrets - This is mostly done after the entire cycle is over or that particular round is finished (depends).