Most forms ask you to fill your parents name and they also ask you to fill your reservation group, that is general, OBC or SC/ST(schedules class/tribe).
A lot can be gathered from this.
Even if you lie, there are background checks for this.
The smarter parents, register their kids as something generic like "kumar" or "singh" in schools.
Interesting, I've often seen CVs from people applying from India include their parents' details. I assumed it was something to do with caste but I was still surprised to see it added even when not required.
