If you want to move chat to right side, follow the given steps.Step 1: Click on the gear icon at the top right side of the page and select settings.
Step 2: Here select ‘Labs’ tab. In this tab, search form “Right-side chat” Gmail feature. Enable this feature and then save changes.
It will save changed and then reload your inbox. Now you will find your Chat at the right side of the page.
Now if you want to move chat back to left side, follow the same steps and then disable the “Right-side chat”.