Is their any Command or option in Google Developer Console to get the object and sub directory count in google cloud storage bucket.
I don't think there is such option in the developer console. I think the best way to count objects is to use gsutil (https://cloud.google.com/storage/docs/gsutil?hl=en)? You can use commands like "gsutil ls gs://bucket/** | wc -l" to count the number of objects in a bucket.