I have tried the below code
//which i visually see taking me to 5thtab)
//After this it failing from below step as null pointer
// I find that Windows.getWindowHandles().get(0), not tried yet but i dont see it i katalon this supports?
I found this similar discussion: Switching between Tabs in Chrome issue - #6 by costea.georgian89 and please try their suggestion.
Sorry @Elly_Tran. The OP is inquiring about Windows Desktop testing. There are desktop applications that arrange similar options together in a container that have tabs that are either across the top of the panel or down the side. The image below is an example (from a school project) with tabs across the top.
However, the link you gave is for Web testing with browser tabs.
Edit: Maybe you can enquire with your “Windows Desktop” team and see if they have any suggestions?