Hello Raj
If you are looking to configure most of your users for Basic Mobility in Intune, you can assign them a "Basic Mobility" security group that has been configured with appropriate policies and settings for basic device management.
To address the license error issue in the Company Portal app for users who do not have an Intune license assigned, you have a couple of options:
Remove the Intune license from the user: If you do not require full Intune management for certain users and only need Basic Mobility, you can remove the Intune license from their user account in the Microsoft 365 admin center. This will allow them to use the Company Portal app without encountering a license error.
Use Intune App Protection policies: Instead of assigning an Intune license to these users, you can deploy Intune App Protection policies to manage and secure the apps and data on their devices. App Protection policies do not require an Intune license for the user but can provide basic security features for company data within apps.