Roy's novel can be viewed as a complete indictment of patriarchy. Male-dominiation in all things is the norm in India, whether the domination be in the realm of political, social, or financial arenas.
There is an interesting article about India's patriarchy and Roy's views on the subject, "Arundathit Roy and Patriarchy" by Kalpana Wilson. I have excerpted a poriton of Wilson's article here (a link to the full article appears below):
Wilson arugues that patriarchy in Roy's novel is inseparable from its intensely personal themes of love, memory and loss is a savage indictment of patriarchy, and of its specific character in a semi-feudal, backward capitalist society.
Arundhati Roy is the only woman in the oft-cited list of top-ranking Indian writers in English. Her anger at the crushing and destructive effects of patriarchal oppression runs through the novel, making it explicitly political... Clearly, "The God of Small Things"who is to commit the ultimate transgression by loving the low-caste Velutha, epitomises this. Roy by turns mystifies and explains Ammu's ability to resist in small ways: 'Occasionally, when Ammu listened to songs that she loved on the radio, something stirred inside her. A liquid ache spread under her skin, and she walked out of the world like a witch, to a better, happier place. On days like this, there was something restless and untamed about her. As though she had temporarily set aside the morality of motherhood and divorceehood...".