Why Ronita was not allowed to dance but Nishan had to?

Can someone pls explain? I don't get it so Ronita got a break because Rohit is sick? So they are not in voting and will automatically be in next round without dancing and subjected to voting? 

This is damn unfair for nishan I have to say this even though I don't hate Ronita. Both nishan and Rohita was in same situation; doctor advised complete bed rest for both 

 and yet nishan didn't get a break when Nityami couldn't even stand. 

Grateful if someone could justify this logic 

Logic is Anitha is a very popular face and channel is milking on her cute love story.

Where as shantanu is still a begginer who does not know how to act in a reality. ( I hope u get my sarcasm here)