I think this is what going to happen now:
NT will die from this shock and fall. Dev will be really upset when his mom dies and will blame Kajjal for his mom death as she exposed everything to NT. He would be so mad at Kajjal that he would not like to marry her for the time being...he would tell her that if she doesnt want to believe her that its her problem, but now he has bigger issue to solve, which is to expose K and A.
On the other hand Karan and Ameesah will be really happy that both NT and Dev are dead. Dev will pretend to be Raju and would try to expose them.