To get Dolby Atmos you need to have ceiling speakers or Atmos Enabled speakers.
The movie you are playing needs to be encoded in the Atmos/DTS-X format.
Your receiver's speaker settings should be set to an Atmos configuration (5.1.2, 5.1.4 or 7.1.2 - top front/top middle etc.).
Your source (Blu-Ray player or gaming console Xbox or Playstation) should be set to bitstream.