Usecase :- My test contains 5 Thread Group. Each Thread Group is having one loop controller with loop count 2 and all the HTTP requests inside it.I need to execute first loop iteration and pause the loop iteration then execute next thread loop's first iteration and pause until first loop iteration completes of all the Thread Group. The reason of doing that is i need to compare page size in case of without cache and with cache.
It should be enough to have 2 thread groups: one with HTTP Cache Manager and another without the HTTP Cache Manager. Remember that the HTTP Cache Manager works only for Embedded Resources (images, scripts, styles, fonts, sounds, etc.) and given well-behaved JMeter test should have the same network footprint as the real browser - your use case "without cache" doesn't have a lot of sense as I don't think that a "normal" user would disable/clear cache in his browser before accessing next page of your application.
If you still want to accomplish your scenario consider going for Inter-Thread Communication Plugin which can be used to pause other thread(s) even in different Thread Groups while specified condition is met.