Suite Commerce Base theme are not displayed in list of extension manager even after installing the Suite Commerce Base theme bundle. In order to solve the issue follow this steps

- Navigate to Customization > Lists, Records, & Fields > Record Types
2. SC ExtMech Extension: Click List
3. SuiteCommerce Base Theme: Click Edit
4. Target_Version: Clear value
5.Click Save
6. SuiteCommerce Base Theme: Click View
7. manifest.json: Click Edit
8. target_version:Remove on the code
9. Click Save
