First, I will assume that you created a mew Linux account named "jboss" and that you are running the app server using that account. I will also assume that you changed ownership of jboss_home (and all of the files and directories it contains) to "jboss". Then I will also assume that you used chmod to provide the correct access.
Given all of those assumptions, any new file created within jboss_home has the same restrictions as what you set up already.
Things you never mentioned in you post: where is the file being create? What restrictions do you have set for the existing files? What restrictions to you want for the new file (if you want different restrictions than the existing files.)
Also by "We have to restrict read access for others in linux" do you mean you want other to only be able to read the file (no write access), or that you do not want others to be able to read the file. I could interpret your statement either way, though I would lean towards not allowing anyone to read the file.