I visited the site with the article and it is "suspended" However HT has an article that elaborates
Surprise! Nearly half of IndiGo foreign-owned - Hindustan Times
From what I can understand Calieum investments is owned by an NRI who was also the ex CEO of US air. About the similar pattern 9W had before it went public and not breaking any rules.
DGCA is working on a plan for FDI from foreign carriers regardless of public or private. I have searched their website for a reference to what you are mentioning but cannot find that.
A private exercise in Delhi seems to have helped so lets hope the other airports get privatized soon.
DGCA has in past 18 months stopped the control of ticket prices to a great extent so that is behind us and fares have zoomed up.
That said the new minister seems to be taking some tough calls to send a message out so fingers crossed.
I still stand by my assertion it is the people and the system and not the government.