Due to the description of Table 1-2 in "https://docs.oracle.com/en/database/oracle/oracle-database/19/drdaa/intro-to-tools-and-products-supporting-migraiton.htm… ", that sql server 2012 not listed in that table.
So I wanna know that is actually support or not.
Not officially, although it should be possible. Newer SQL server features may not be supprted for the migration and require hand coding.
Work is underway to modernize the migration tech..both on how we deliver it and the platforms supported.