Re: If Navigate server is exposed over internet and Windchill is in intranet is there any acessibility problem
If Windchill and ThingWorx Navigate server are able to talk to each other without any issues over the network, there should be no problem accessing Windchill data from ThingWorx Navigate. If you face any problem with this configuration feel free to create a TS case.
It would be best for Support Services to investigate this further if it doesn't work. A case can be logged with TS here.