For NRR to come into play, some very specific things need to happen. If we lose to SA we're basically out of the tournament barring major upsets. If we win all of our games, the only way NRR comes into play is if SA beat India, and one of our games gets rained out. That is, unless another one of SAs game gets rained out, in which case a 2nd game of ours needs to be rained out.
I mean.. yeah it MIGHT come down to that but why worry about this scenario at the beginning of the tournament? Humse 130 nahi baneahe aur tumhe NRR ki parri hai?