Define different firebase rules for different bucket

I have these rules in my firebase:

{
"rules": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
}
}

Now, I want to define rules for one project bucket named “INFO” which I want to be readable by all but writebale by none. How to modify my rules accordingly? Plz help me anyone