Very interesting insight.
To be rigorous, we have to define what ‘middle class’ means.
If middle class means ‘someone with a steady white collar job’ , then it is entirely possible for someone with income of 8–9LPA or even higher to be considered middle class.
Is ‘middle class’ an income (or wealth, to be more accurate) stratification method or a social identity?
A white collar worker might be inclined to see the landowners, businessmen etc as the upper class and themselves as the ‘middle class’.
In US, the notorious “L Curve” defines the breakaway point between the elite and the rest. Would be interesting to see if similar data exists for India. Was there a specific reason why 17LPA was chosen as the boundary point?