As for the selection round, what song should be sung and what will be the judging criteria?
In the selection round, the same rule applies as the audition round i.e. the participant can sing a song of his/her choice and not necessarily the same song he/she has sung in the previous round. In this round the judges will be judging on the previous parameters (voice, tune, rhythm, pronunciation and expression) and in addition they will be looking for overall performance.