This is how this show is scripted

So when they announced the top 2 (sreeram and irrfan) after giving their individual performances in the grand finale, the audience is expected to believe that the contestants didn't know if they're in the top 2 till the results were announced. However, right after that, Sreeram and Irrfan somehow managed to perform one last time as the top 2 contestants of the show. For that kind of a performance, they probably practiced and rehearsed for a whole week prior to the grand finale. Which directly means that they knew who is going to be in the top 2, and who's the winner of the show.