First of all I admire Niketan because he is the only male in this house that maintained his grace and dignity through the show and is using his sharp mind to win the show as compare to those good for nothing male contestants who are trying to get all footage because of their linkups with females.
As for his relation with Urvashi is concerned, remember in the very start of the show, Niketan told Sidhu that the strongest group in the house is the Mahila Mandap group (Delnaaz, Aashka and Urvashi) and in order to win the show they have to dissolve this group. First Rajneeti task and then Gulal Task in which Urvashi's group mates didn't supported her fully were the high points when she was ready to left her group and he took advantage of this opportunity by taking her in his group. He finally did what he wanted i.e. dissolved the most powerful group. It doesn't mean that Urvashi was a fool; she also had no other option than to join him because she has an aggressive personality and Aashka's OVER-SENSITIVE NATURE and Delnaaz PLAYING TOO SAFE ATTITUDE doesn't harmonize with her nature at all. Otherwise she nominated Niketan two times and both times she called him very calculative, shrewd and manipulative person.
So all the fans of Urvashi & Niketan FRIENDSHIP, please wake up it is just a Strategic Alliance that they both are maintaining to win the show by following the rule of 'Keep your friends close and your enemies closer'.