As per a UNESCO related report released in October 2013, approximately how many internal migrants were there in India at that time?

Introduction / Context:
Internal migration within India is a major social and economic phenomenon. International organizations such as UNESCO and other research bodies have highlighted how many people move within the country for work, education, or family reasons. This question checks whether you recall the approximate figure quoted around 2013.

Given Data / Assumptions:

• The reference point is a UNESCO related report released in October 2013.
• The report discussed internal migrants within India.
• Four rounded figures are given as options: 200, 400, 600, and 750 million.

Concept / Approach:
Different census years and reports use slightly different numbers, but the important point is the order of magnitude. Around three to four hundred million people in India can be classified as internal migrants in the broad sense. The correct option will be close to this widely cited range.

Step-by-Step Solution:
Step 1: Remember that the report Social Inclusion of Internal Migrants in India highlighted that roughly three out of ten Indians were internal migrants.Step 2: Three out of ten of a population above one billion means a figure slightly above 300 million, and many summaries round this to around 400 million for the next census period.Step 3: Among the options, 200 million is clearly too low for a country as large as India.Step 4: Figures such as 600 million and 750 million would imply that more than half or almost three fourths of the population were internal migrants, which is not what the report stated.Step 5: The most consistent rounded figure with UNESCO based reporting in 2013 is 400 million, representing the broad scale of internal migration.

Verification / Alternative check:
Summary notes on the UNESCO report and related analyses often mention that India had more than 300 million internal migrants as per older census data and that later estimates place it closer to 400 million. Exam oriented GK books also commonly give 400 million as the answer for this question.

Why Other Options Are Wrong:
200 million: This underestimates the internal migrant population and does not match the three out of ten Indians figure.600 million: This suggests that nearly half to more than half of the population is internally mobile in a given period, which is higher than reported.750 million: This is even more unrealistic and would imply that almost the entire adult population is migrating inside the country.

Common Pitfalls:
A common error is to ignore the population proportion mentioned in discussions and guess based only on which number seems impressive.Another pitfall is confusing internal migrants with urban population or with all people in the working age group.

Final Answer:
According to the UNESCO related report around 2013, India had approximately 400 million internal migrants.