This is what I felt,
All the kids sang equally well in that episode with little bit of mistake here and there. Infact Amir's song was near flawless, I liked his the best. If Anamika and Tanmay can get A+ with not so perfect singing, why not Amir. Thought he deserved A+ too compared to Tanmay and Anamika's singing. Even Rohanpreet's and Vasundhara's performances were as good as Tanmay's and Anamika's with few mistakes like them.
May be the reason Anamika getting A+, she of course sang well but not exceptionally well , is it because she had chosen an off-beat song(not the stereotype songs usually sung in these special episodes) or to keep her vote bank alive(after all that happened in the previous episode). She is surely going to top 3, as she is the only one representing east voting bank. Now looks like Tanmay is getting lots of votes for Zee, that's bad news for Amir since both represent the same zone. Anyday anytime my choice will be Amir over Tanmay. Between Vasundhara and Rohanpreet, to me looks like one of them will make it to top three since they both represent the North.