I would argue that the voip issue is not a neutrality one but a national security one. The reason for obtaining a license us not financial but law enforcement oversight.
I'm not justifying either way, but I don't think it has anything to do with neutrality in its economic sense
The proposal to regulate VoIP apps is before TRAI only because of lobbying by telcos who are still in denial over the world moving towards data and want to hold onto their voice call revenues.
I'm not sure what purpose licensing will serve from a law enforcement perspective. Banning VoIP apps that refuse to apply for a license will be like playing whack-a-mole as people can easily add a VPN to get around it or the service can intelligently route traffic to get around the ban.
On the other hand, unlicensed VoIP apps would not be allowed to advertise in India, whether that's on TV, billboards, newspapers, or popular Indian websites. They would likely not be allowed to be sold in the Indian locale of Google and Apple's app stores. A communications app that few have installed is close to useless - even in countries with significant freedom, we use Facebook Messenger, Hangouts, Whatsapp and Snapchat over alternatives not directly controlled by major companies, because the free alternatives don't have the funds to convince all your friends that they're legitimate.
I'm not justifying either way, but I don't think it has anything to do with neutrality in its economic sense