@karthik palani,Thanks for posting in Q&A.
To clarify this issue, please check the following.
1.For Android/iOS you need to have the Company Portal/Authenticator app installed as it is the broker for Intune APP to work. Without this your APP condition in CA will not work.
2.Have you configured MFA to register device in Azure AD?
3.Please check the app protection policy deployment status
4.Could you please share the settings of CA policy with us?
Also, here is a thread with the same issue and someone has solved successfully you can refer.
https://www.reddit.com/r/Intune/comments/12do44k/help_with_conditional_access_require_app/
Non-official, just for reference.
Please try above information, if there is any update, feel free to let me know.
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