Keras exception: Error when checking input: expected dense_input to have shape (2,) but got array with shape (1,)
Yoy always need to pass the data for prediction in batches, although this batch is of size one (one sample). Try changing this line:

x = np.array([house_size, bhks])


into this: 

x = np.array([[house_size, bhks]])


This should work.