Upgrading Sitecore CMS 5.3.2 rev. 090212 (or later) to Sitecore CMS 6 can be done with the help of the Sitecore CMS 5.3 to CMS 6 Database Conversion Tool which is available via the following link:
Upgrading versions earlier than 5.3.2 rev. 090212 to Sitecore CMS 6 requires a two-step process:
- Use the Data Migration module to upgrade the solution to version 5.3.2. The Migration Wizard allows to transfer data from the following releases of Sitecore: 4.3.2.x, 5.0.x, 5.1.x, 5.2.x.
- Then use the Sitecore CMS 6 Database Conversion Tool to convert the databases to the database format used by Sitecore CMS 6.
To upgrade Sitecore 5.3 to Sitecore 6.3 you should first upgrade your solution to Sitecore 6.2 and then to 6.3 using the appropriate instructions.