Hey Aman I just saw your vid of Mahi - great work dude! I've only listened to it once and not very carefully, so I could be wrong in what I say, but I'll say it any way! Ki farak penda hai!
I think if you sang like this in an Indian Idol audition, there's a 95% chance that you'd get through!
But just to point out some areas of improvement (I'm sure you're working on them anyway). You were actually good at all these things in your song, but just a bit inconsistent. So here goes:
1. Holding notes - make them less shaky
2. Finishing notes - finish off your lines with more confiidence
3. Open your mouth a bit more for some of the lyrics
But overall, that was an excellent attempt, considering it was without any backing up or anything.