You need to have the latest Chrome (v83) version to activate this feature. To do this:
Click three-dot menu and go to - Help > About Chrome
After that, Chrome will initiate updating. Restart Chrome, and you can use the feature. Just right click any tab and you can add it into a group and customize colors and name the group.
If you can't use the feature after update, go to address bar and copy-paste this "chrome://flags/#tab-groups" and "Enable" the feature.
(Translated from https://teknobur.com/google-chromea-sekmeleri-gruplandirma-ozelligi-geldi-iste-yapmaniz-gerekenler)