How to cite a chapter from a report with different authors? I have to cite a multi-chapter report. Every chapter has different authors. Should I cite with the name of the main author and then the specific chapter? Or should I use the first author of the chapter I am citing?

If the main author is Smith but Jeff is the author of a chapter where Smith is not in the authors’ list, should I cite with “(Smith et. al 2000, Ch 6)” or “(Jeff et. al 2000)” and then add a citation for each chapter in the cited literature section?
If authors are identified for the chapters, then this document is best treated as an edited collection. In this case, the chapter authors are the author and the chapter title the title. The overall report title is then the collection title (filling a similar role to journal title) and the "main" authors the editors.

The exact details of how this is formatted depend on the style where you are submitting, but if any names are appearing in the main text, they are of the chapter authors.