I have some analysis.
As the data comes in NOTA is more than the margin of defeat.
Who are NOTA?
They are young and not so young, educated, middle class. And I suspect majority are of so called high caste.
Middle class is angry because Jaitely taxed their small saving and return from small investments like SIPs. Their monthly income ranges from 50,000/- to 2,00,000/- per month. Yes, these people do not complain openly, but grumble inside. Highly Nationalistic attitude and selfish to some extent.
To mend the defeat, BJP must do (but god knows why they don't)
1. Give tax and other benefits to middle class.
2. To retain UP vote, bring Ram Temple bill to Paliament (Don't care if it is defeated). Because it will at least expose who supports temple who not.
3. For nationalistic people bring removal of Art 370 bill in this session. I know this will be defeated, but will again expose many.
3. Do something for Tribals.
The above four kinds have reduced their votes.
Rajasthan is still with them. Remember the slogan " Modi Tujhse koi Bair nahin, Rani tera khai nahin".