For this question, let's use a bottom-up approach:

Step 1: Estimate the number of households in India.

India has approximately 300 million households.

Step 2: Estimate the percentage of households that have access to the internet.

Given the increasing penetration of the internet in India, let's assume 50% of households have internet access. This gives us approximately 150 million households (300 million * 50%).

Step 3: Estimate the number of these households that order from Amazon.

Not everyone with internet access will order from Amazon. Based on e-commerce adoption rates and the presence of other competitors, let's assume 20% of these households order from Amazon. This gives us approximately 30 million households (150 million * 20%).

Step 4: Estimate the frequency of orders per household per month.

On average, let's assume households order twice a month from Amazon.

Step 5: Estimate the number of items per order.

On average, let's assume each order contains 3 items.

Step 6: Calculate the total number of items sold per day.

First, we need to estimate the number of items sold per month. This is the number of ordering households * frequency of orders per month * items per order, which is 30 million * 2 * 3 = 180 million items per month.

Now we can estimate the number of items sold per day by dividing the monthly total by 30 (assuming an average month). That gives us approximately 6 million items sold per day.

So, the estimated number of items sold on Amazon.in in a day is around 6 million.