First, you need and install MsSqlToOracle.
MsSqlToOracle is a data tool that helps DBA and database programmer convert SQL Server data to Oracle database.
Convert data from SQL Server To Oracle – 4 Steps
1. Open Source SQL Server table.
2. Select a destination Oracle table and config fields.
3. Preview data.
4. Convert.
More about MsSqlToOracle – the tool to convert SQL Server data to Oracle.