I think the cutoff is based on percentile(Not sure) which means it varies based on how the students perform in that year. So the 30% score would be the cutoff.
What the article means is that a candidate might have scored overall high marks but didn't clear the individual subject cuts so got left out. I think thats fair. You don't want one subject wonders getting in.
About the cutoffs, mere zamane mein aisa nahin hota tha
