This is the 3622nd most frequent Turkish word.
tamamının
"Of all of it" or "of its entirety."
In this context, "tamamının" means "the entirety of" and refers to the whole content of the book.
Bu kitabın tamamının okunması gerekiyor.
It is necessary to read the entirety of this book.
Here, "tamamının" is used to mean "the entirety of" in addressing the scope of what was presented.
Gösterilenlerin tamamının doğru olmadığını biliyoruz.
We know that not all of what was shown is correct.
In this case, "tamamının" indicates "the entirety of" concerning the entire project and its completion.