Advanced Encryption Standard I had done an example on AES-128 bit.But while doing AES-192 bit,i am facing below problem. 
what is the order of the matrix after mixed column step in 192 bit AES?
what is the order of the matrix after mixed column step in 192 bit AES?


The only differences between AES-128 and AES-192 are


the key scheduling is different
AES-192 has two more rounds. 


There is no difference in any of the steps.

What you might be trying to look at is Rijndael with a 192 bit block size; there are differences in the shift row steps, which might be what you are looking at.  However, that has little to do with AES, which always has a 128 bit block size.