Why the bigg boss is hell bent on keeping Rajat inside the house? Probably the BB is worried that this would set a trend. People who want to quit may start faking. What should be done in his case? What if everybody start faking ill health to quit? But I feel the guy has a genuine problem.
If he is not faking (I think he has a genuine problem)
BB wants to give an image to the contestants, where the contestants cannot violate the contractual agreement. So, even if he is sent, he will be sent as per the eviction policy i.e. based on the viewer's vote(If the viewer's votes are really considered)
If he is faking
He knows that there is no nomination issue in Heaven and so he can stay as long as he likes, only the thing is, he should act. Everybody knows that he can't squat. So, nobody wants to send him to hell. He will stay in heaven until everybody loses patience. So for that many weeks he will be escaping nomination. People like Kamya, who most of the viewers feel as strong contestant, is under the sword of elimination. But Rajat will happily sleep in bed, enjoy the comforts of Heaven and escape elimination.