I don't think what Nishant did was unexpected or even wrong atleast not towards TejRan. Yes Jay should feel betrayed but he seems to be happy being the one who gave the idea of ousting Karan to Nishant as I saw him bragging to Neha in a LF clip.😆 I haven't watched the episode so dont know how fair the sanchalan has been but let's look at possible scenarios,had someone else won :
For instance, had Karan been the winner - Nishant and Vishal out, Simba, Rajiv/Jay in
Same choices for Umar and Teja.
It would've been interesting to see who Vishal would've chosen. He has been playing from behind the shadows and this wud've been a tricky spot for him. ..My guess is he would've kept Teja because they have a bond and maybe removed Karan and Umar..or Karan and Nishant.. and gotten in Rajiv and Simba. Or Neha but I doubt anyone wants Basin in VIP room..
Point is had TejRan won, Nishant would've been out along with Vishal. So I dont see Nishant's decision as backstabbing.. I would've loved to see him or Vishal break TejRan so that they are forced to play individually. But still this is not a bad situation at all.. none of the contestants should get too uncomfortable for too long.. that's the whole point of twists.