I am trying to start the Google Cloud shell but it does not launch.It keeps on saying "Connecting: Establishing connection to your Google Cloud Shell..." but nothing happens. I am under a company's network which might be a reason. How should I debug this?
You can try to access with a different browser, such as Mozilla Firefox in incognito mode to prevent unintended behavior from browser extensions. You can also try to access from another computer behind a different network. I would recommend, run Cloud Shell in safe mode by appending cloudshellsafemode=true to the URL [1].
[1] https://cloud.google.com/shell/docs/features#safe_mode
EDIT (adding the comment below for clarity):
If you are using a corporate network is highly probable that your IP address in behind a proxy, in that case, you need to work with the company system administrator to enable access to the possible IPs that are assigned when a Cloud Shell is launched.
You can get the aforementioned IPs by running this:
google_ips=$(for LINE in `dig txt _cloud-netblocks.googleusercontent.com +short | tr " " "\n" | grep include | cut -f 2 -d :`; do dig txt $LINE +short; done | tr " " "\n" | grep ip4 | cut -f 2 -d : | sort -n | xargs | tr " " ",") ; echo IPs: ; echo $google_ips