I have created my project in python and google cloud datastore, now i want to create my project admin panel in node JS. Is there any way to use both python and node js on same domain on google cloud?
e,g my project url is http://lynkweb-165106.appspot.com/
and i run both node js and python over on above url
Yes. You can develop the admin panel as a new, separate service/module of your app.
Services have code-level isolation (see Service isolation) so the choice of the GAE environment (standard/flexible) or the programming language used is done at the service level and can differ from a service to another inside the same application. See also is it possible to have a hybrid PHP+Java web application on Google App Engine?
As for the DNS mapping you can keep both services under the same domain, but you will need to establish clear, non-overlapping URL path patterns in your app.yaml (or equivalent) config files to be able to route the incoming requests to the proper service.
For example:
You may need to use a dispatch.yaml file for inter-module routing, see Routing with a dispatch file
You may be running in a few problems as first. When debugging pay attention to your catch-all app.yaml patterns like url: .* and check your logs (for all services) to see if the requests are being handled by the right module.