Why my brave browser shows like this

I’m not sure but it looks like you are using an outdated browser. Please check on your app store if there is an update available.

@Itzmesiva did you have a rooted device or custom ROM installed?

No this is updated app

No my mobile not rooted

Basically, it’s shown because your device failed the Safety Net check which is required in order to enable Rewards. I’ve no workaround for that for now.