In my opinio, I would rank Vinit, Nihira, Himani, Hemchandra, and Debojit.
Also, who made ZeeTV or Sa Re Ga Ma Pa an expert in SECTION PROCESS of "India's Voice". How come no country in the world select their leaders by having people call-in. The selection process has to be CONTROLLED.
I think instead of people calling in, it would work better if Sa Re Ga Ma Pa selected some people (say 100 people) who know much more about music. Each episode should have different people. Get vote from them and then make the decision. I am not saying this IS the best selection process, but something like this which is more visible and controlled. Then you would truely get a good Indian singer.