is it possible to integrate Robohelp 11 with Azure DevOps server for version control?
Never heard of that one being used. Doesn't mean that it's not possible, but I don't think there's anything built into RH (any version) that mentions Azure.
I found an article that actually describes how to integrate RoboHelp with Azure DevOps, but there is no mentioned which RoboHelp version is support and also I don't see the "Collaboration" option in RoboHelp 11.
Ah - RH2019 - the "... select a RoboHelp project file (.rhpj)..." line gives it away. RH11 would be opening an .xpj file.
RH11 uses MSSCC Provider to connect to older versions of TFS. I'm not using source control at this time so can't provide any actual advice.
Having said that, I've found a few articles that may help.
I found this article for connecting older versions of visual studio to new TFS versions. So it might be possible?
There's also this older article about version control with RH. The 'Setting up version control' heading at the bottom of the page lists the basic requirements for older TFS/RH.
Your tech guys might be able to determine if it's possible using this info.