You will be not able to migrate from SQL 2000 to 2012 directly. Migration from 2000 to 2012 requires an intermediate step.
SQL Server 2012 supports upgrade from only the following versions: SQL 2005 SP4 or SQL 2008 SP2 or SQL 2008 R2 SP1.
If you try to restore a backup database from SQL Server 2000, you will get the error number 3169 with the following message: The database was backed up on a server running version %ls. That version is incompatible with this server, which is running version %ls. Either restore the database on a server that supports the backup, or use a backup that is compatible with this server.
You will have to make the migration in two steps:
Step 1: Make a first migration from SQL 2000 to SQL 2008 for instance. You need to be SQL 2000 SP4 before doing this
Step 2: Make a second migration from SQL Server 2008 to 2012.
if you are afraid of the licensing issues, you can perform a side-by-side upgrade by restoring or attaching the SQL Server 2000 (SP4) database to an Evaluation copy of SQL Server 2008 R2, and later backup/detach the upgraded database (on SQL Server 2008 R2) to restore/attach it to SQL Server 2012.
For more information, please see the following document:
Note : SQL Server Upgrade Advisor is available for 2012 : Microsoft Upgrade Advisor analyzes instances of SQL Server 2005, SQL Server 2008, SQL Server 2008 R2 in preparation for upgrading to SQL Server 2012. Upgrade Advisor identifies feature and configuration changes that might affect your upgrade, and it provides links to documentation that describes each identified issue and how to resolve it.