How to find which plugin is taking maximum resources

can someone please help me here ??

Best bet is usually to check error_log.

Have you got a plugin throwing a lot of messages?
If your log file is big, you can delete it (it will get recreated if more errors appear).

Another thing to look at is: https://gtmetrix.com/
It’s mostly client side, so it possibly wont be too useful for narrowing down on a plugin… it may give you other ways to reduce the size of (and thus, simultaneous requests upon) the site.

What is the site?

Perhaps debug objects plugin might be useful.

thanks guys I will try the two methods mentioned above
Thanks jack and vjpo

P3 (Plugin Performance Profiler)
“See which plugins are slowing down your site. This plugin creates a performance report for your site.”
https://www.ads-software.com/extend/plugins/p3-profiler/