To apply for Migration Certificate, you should send your application along with fee to the Deputy Secretary, Central Board of Secondary Education, Regional Office(the state, where you have studied your 10th class).
You can also go through this official link of CBSE. This will provide you all the reqirements :-
https://www.google.com/url?sa=t&source=web&rct=j&url=http://cbse.nic.in/faq/dupform.pdf&ved=2ahUKEwjUlN_48-_hAhWf8HMBHdtFCA0QFjALegQIAhAB&usg=AOvVaw2mQaPt1PhGq4FVYkIYR0PH
Hope it is helpful!!!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile