I oppose internet.org due to the permanent damage that it will cause to the Internet itself. Please see my earlier comment for how this will happen.
Internet.org probably won't shut down even if strong net neutrality is legislated in India; they would merely change their program to be compliant, by using a data cap on free (beer and freedom) internet use.
The cost for ISPs are the same in either scenario. The fiction about internet.org being "cheaper" to provide than the open Internet doesn’t hold water.
Internet growth in India: 20% of Indians have Internet access today, a number that has grown at 30% annually for the last five years. Mobile phone use grew from 20% to 75% in five years, so it is likely that Internet use would also get there by 2019 without internet.org.