The 2011 Census of India categorized the working population into four major categories. Let`s analyze each option to understand which one is not included in the categories:

Option 1: Cultivators - Cultivators are individuals involved in agricultural activities and are directly engaged in growing crops. This category is included in the classification.

Option 2: Domestic workers - Domestic workers are individuals employed in households for various tasks like cleaning, cooking, and child care. This category is NOT included in the classification. (Correct answer)

Option 3: Household industrial workers - Household industrial workers refer to individuals involved in home-based industries, where they produce goods such as textiles, handicrafts, or small-scale manufacturing. This category is included in the classification.

Option 4: Agricultural Labourers - Agricultural laborers are individuals who work on farms or agricultural fields but do not own the land they work on. This category is included in the classification.

Therefore, the correct answer is option 2: Domestic workers. They are not included in the four major categories of the working population according to the 2011 Census.