i am not able to find jenkins config in /etc/sysconfig/jenkins

What are you trying to configure?

And what is your defined JENKINS_HOME? you may be able to start looking there.

afaik /etc/sysconfig/jenkins is the old location when jenkins was managed with initd.
Now with systemd way, the config is not there anymore.
Check Linux and
Managing systemd services

at least in my system:

if Jenkins sign into the web ui and visit: {JENKINS_URL:PORT}/manage/configure and you can see the assigned directory.

If the app isn’t running you can try to sign into the server where it is installed and try the bash command

$ whereis jenkins

I get a simple response with 3 locations to check. in my case /usr/share/jenkins contained a file migrate. read that file with a filter of HOME gave me the locations directory…

cat migate | grep HOME

At least in my case that worked, maybe you will have similar success with those options. Else someone smarter that me (not that hard) will give you better results.

Best of luck