I understood your views regarding the militarization of Police forces (this is a much bigger issue in the West, particularly the US, than in India). But while I concur with your opinion regarding much-needed large scale Police reforms, I must reiterate the importance of tactical intervention units within the Police force.
The key aspect here is time. The time it takes for a central unit like the NSG (in spite of the regional hubs) to respond to a situation requiring their expertise is simply not acceptable (not to mention the obvious inter-agency coordination issues that can & will emerge as a situation develops): as it has been concluded time & again across the world that one of the most significant (if not
the most significant) roles in curtailing an active shooter (can be a terrorist or otherwise) is performed by the
First Responders on scene. When the situation does go bad, NSG will have to come nevertheless, but the First Responders to any such incident, especially in a metropolitan city, will HAVE to be the Police.
The better equipped these first responders are, the better the chances that the shooter(s) will be subdued before they get an opportunity to cause further damage. Having a well-equipped tactical team available for tasking at short notice, placed within the command of the Police Dept. furthers the efficiency of these first encounters. Kindly go over the events of 26/11. The 'First Responders' had handguns, Ishapore bolt-action rifles and
dandas....while the terrorists had them outgunned with AKs, making the Police unable to effectively return fire or contain/suppress the shooters.
This is what prompted the Maharashtra Govt. to create a unit like
Force One.
Pic credit: INDRA Networks
Bottom-line from my side is: militarization of Police is but a cause-and-effect situation. Why Police units need the kind of weapons & equipment that previously only the military used to have?
It's because the needs demand it! When you have terrorists with full-automatic assault rifles shooting up cities like Mumbai, you obviously can-not and must-not make it so that the response comes in the form of 9mm handguns and revolvers!
Firepower is but a tool to gain immediate tactical advantage over the opponent.
I'm of the genuine opinion that most of the 'militarized behavior of Police creeping over to their behavior toward citizenry' aspect you are concerned about is actually NOT much of an issue with Indian Police...at least nowhere as much as it is with their American counterparts.