Step 1: Define National Income.
National income is the total value of all goods and services produced by the residents of a country during a specific time period, typically measured annually. It is used to assess the economic performance of a country.
Step 2: Concepts of National Income in India.
India, like other countries, uses several measures to assess national income, the most common of which are:
- **Gross Domestic Product (GDP):** The total value of goods and services produced within the country's borders in a given period, without considering income earned by residents abroad.
- **Gross National Product (GNP):** GDP plus the net income earned by residents from abroad, i.e., income received from foreign investments minus income paid to foreign nationals.
- **Net National Product (NNP):** GNP minus depreciation (the loss in value of capital assets).
- **National Income (NI):** The total income earned by the residents of the country, which is also the sum of wages, rents, interests, and profits. It excludes income earned by foreign nationals within the country.
- **Per Capita Income:** The average income per person, calculated by dividing the national income by the total population.
Step 3: Conclusion.
Thus, national income in India is measured using several concepts that reflect different aspects of economic activity, such as GDP, GNP, NNP, and Per Capita Income.
Final Answer:
\[
\boxed{\text{National income concepts in India include GDP, GNP, NNP, and Per Capita Income, which reflect different aspects of the economy.}}
\]