Web server
How to catch 500 error from error logs in apache
Catch 500 error
How to check the installed mod_jk version
If you have that already installed then if you have enable mod_jk log then you can check from that log file or you can do
http://Your_SERVER/ApplicationURL/SomeFOLDER/@#@#CS<>>$#$#$%
You will get internal serever error over there at the bottom you will get the mod_jk version with apache version.
e.g.
Apache/2.0.59 (Unix) mod_jk/1.2.28