How to enable Smart Tagging in AEM 6.2
Smart Tagging requires additional AEM licensing. Contact Adobe Sales to ensure that you have the proper licensing to use this feature.
II. Apply the latest 6.2 Service Pack and Cumulative Fix Pack
Apply the latest fix packs for your AEM6.2 environment. That would update your Smart Tagging features to work similar to AEM6.3.
III. Follow the documentation
Follow the documentation on Smart Tagging: