HI,
There is a great shortage of rooms in the Khanna's house. When angad and kripa came back then naina told karthik to leave angad's room for it was actually angad's. and then karthik was asked to stay in he guest room.
This is total foolishness by Ekta. It's not possible that in such a big house , Karthik doesnt have a room! Well i wonder where he used to stay before angad had gone to jail!