Nikki is living in a bubble of inflated praise. She is being overly propped because she brings drama and TRP. The way Salman silenced her when Jas was speaking was an indication toward that.
(again saying I dont like Salman involvement.. I would rather like a contestant continue to go downhill or uphill but without any info from outside world. Salman practically butchers BB concept every week)
She might be, but she is not fake or rather is not delusional. She admits she is not on some moral high horse but Rubina is someone who actually thinks she is a great person but really is rude and looks down on others.