DataStage is a tool that extracts, transforms, and loads data from source to the target, this is an ETL tool, which IBM acquired from a company called VMark in 2005. Afterward, it was renamed two times and finally, they are named as IBM InfoSphere.
To clear the DataStage training, I recommend you to take up IBM DataStage training from Intellipaat!
This training also includes 40hrs. of industry-based project work which boosts your practical skills in using the tool.