As far as Tanya she is good for nothing. She still bears grudge towards Eklavya eventhough Ansh did nothing to her and she was his friend once upon a time.She was the one to seperate K-N with Ansh. Later she turned good but still came between K-N.Now again she was trying to tell Karan that Sahil did all this for money. Karan has always been selfless and good. If he treats Tanya in a rude way I think she somewhere deserves it.