No it is not bias - the channel has chosen a mix of participants some of whom are trained dancers - like Sushant, Yana, Krushna etc ... and others are untrained - like Akhil, Daya etc ... yet others manage to give a good performance because they are from the entertainment industry and they are young - like Mahi, Ragini,Ankita etc ... but people like Renuka, Shekhar, Akhil, Daya - are either past their prime or have never danced in their lives. It would be unfair to compare them on the same scale as the other participants. If the channel wanted to be really really picky, then they would've chosen participants with similar backgrounds, age and dancing skills - but what would be the fun in that? i.e. if they were all sportspeople who've never danced in their lives as participants who would've watched the show? The judges are going to see progression in dancing, especially for the non-dancers. For the others they are going to be stricter, simply because they are at an advantage. Won't anyone here agree that Sushant is at an advantage over Akhil? And since this is a TV show he ranks more in popularity than Akhil does. So he will definitely get more votes than Akhil.
So to call the judges biased, the channel would have to pick everyone with similar dancing skills, similar popularity, similar age and from the same line of work. But that is not what this show is about.