well,some parts of your argument is right,others are not.you can easily detect a submarine near choke points and if you've some good detection platform.as for bay of bengal,we've good detection mechanism in place.for IOR,we don't need to cover entire IOR,do we???
aint BD is going to get 2 old Ming,which is Chinese derivatives of Romeo class???
SSNs can reach Indian Ocean via the route South of Australia and that is not a choke point.