What about you? If you were a student, and you had to vote, which option would you choose?
I think I'd vote for the best singer overall. Even if a singer performs badly/not up-to-mark in the Ranbhoomi, but he/she is the best singer, I'd give my vote to him/her. I mean, a singer can mess up at times, it's natural.
However, if the decision happened to be between two really good singers, and I just didn't know what decision to make, I'd go according to the performances in the Ranbhoomi.
What about you?