I know i can generate a sql script from a logical model in data modeler, can i do the opposite? i created the database from django and migrate to oracle, o generate an logical model would be really useful.
Yes.
In Data Modeler, File - Import
Choose either your SQL file(s) or use a database connection to import a data dictionary from the database.
This will give you a relational model.
Then you can use the engineer to logical model button to get your logical design and ERD.