How to set different rules for different collection

Question

I want my application read only the language collection data from firebase before authentication only and read data from Users collection only when user is authenticated.

my rules

Answer 1

As far as I can see, you're asking for:

service cloud.firestore {
  match /databases/{database}/documents {
    match /Language/{document} {
      allow read: if true;
    }
    match /Users/{document} {
      allow read: if request.auth != null;
    }
  }
}

With the above any user (regardless of their authentication state) can read the Language collection, but only authenticated users can read the Users collection.