Talking about support matrix, google and firefox are not supported by Altiris in 7.6 or previous versions.
On the other hand, you can do some things that can works, but in my Google Chrome, 48.x version is not working. I'm not able to enable NPAPI (this option does't appear) and tabs that needs silverlight, such as computers, softwares, etc., doesn't works!
What have you done to make silverlight/java work in your google Chrome? I was reading and NPAPI was removed since 42.x versions. http://superuser.com/questions/913201/how-can-i-enable-silverlight-in-google-chrome-42
Regards,