Is JBOSS Application Server supported for real time APIs to connect to deployed RTDS(TREP)?
If yes, which API version is recommended?
Application servers are not supported by the streaming API's; however I have seen many clients use them successfully.
EMA would be the recommended API, and you can view a list of supported platforms, OS, compilers here.
If you are connecting to local RTDS and interested in just getting snapshots, you can also look at the REST web-service provided by ADS. Read more about it in this article.
Please note that if you choose to use an app server with EMA, and encounter an issue, it will have to be reproduced in one of the supported environments - for the development to help you with it.