The pattern cannot be more self evident than in the map above
The North and North east have larger average household sizes, while the east has smaller average house hold sizes. The west falls in between the two. The ones that do not confirm to the pattern are the smaller states and union territories. Kerala, Goa, Daman & Diu and Nagar Haveli on the west and Chandigarh on thenorth have lower average house hold sizes than their neighbours. Similarly NCT of Delhi and Himachal Pradesh and Uttarakhand up north have lower average family sizes than their neighbours. Uttarakhand along with NCT of Delhi and Assam, Gujarat and Mizoram are boderline with an average household size of 4.9
There is a very clear geographic pattern in the size of households in the country