What is the product formed after nitrosation of ketones (HNO2 + ketone)? On C-nitrosation of ketones we get oximes. After this, the oxime formed is hydrolyzed ($\ce{H3O+}$ is added). What will be formed in the end? Does it follow Beckmann rearrangement or what?
Hydrolysis of the ketone oxime gives the 1,2-diketone as reported in this Synlett reference: 


  Treatment of alpha-methylene ketones with excess sodium nitrite and
  aqueous HCl in THF at reduced temperature provieds an effective tool
  for the preparation of a variety of 1,2-diketones