I am facing a bug with Realtime API of Google Drive SDK and I like to know if there is an issue tracker where I can check if that issue is registered and eventually fill a new one.
There are no official bug trackers for the Google Drive service.
There is this page, which lists the known issues encountered using Google Drive :
http://support.google.com/drive/bin/static.py?hl=en&page=known_issues.cs
And this other one that links to Google Drive service's forum, where yo can actually report an issue (look at the proposed categories):
https://productforums.google.com/forum/m/#!forum/drive