Step 1 : When you click on Subject Stream under Manage Subjects sub module under Manage App Data Module, below window will be shown on your screen.
Step 2. Click on the option Add New Stream on the top right of the screen.
Step 3 : Fill up the form, you can choose Mandatory & Elective Subjects by clicking on checkbox. After filling the form, click on the Save Changes option on the bottom right of the dialog box.