As RK said to Bittuji find his weakness and his enemies...so does that mean he is going to shake hands with Bhujang ...if so he doesn't know that to save Sultaan Madhu pointed gun at Bhujang and Bhujang is so cunning that he is going to take revenge from Madhu too...
So ultimately when Bhujang attacks RK has to join hands with Sultaan to save Madhu...and may be Sultaan will get shoot to save either of them and then he start believing his story ...