K.S. Bhagavan's book is only available in Kannada. But apparently it's not about Advaita, but rather about Adi Shankaracharya's views on the caste system. Here is K.S. Bhagavan's summary of his book:
I was first threatened in 1985 when I released my book 'Shankaracharya and Reactionary Philosophy'. My research showed that far from being a social reformer, the Shankaracharya was a strong advocate of the caste system. By going through the text of his teachings in Sanskrit, I could prove that he was vehemently opposed to Dalits and women getting educated.
In any case, for information about Adi Shankaracharya's views on the caste system (which are the same as the views of all the other commentators on the Brahma Sutras), I would refer you to his commentary on Adyaya 1 Pada 3 of the Brahma Sutras, starting with this section. See also my question herehere.