The five-year plans, especially in the pre-liberalisation era, attempted to reduce regional disparities by encouraging industrial development in the interior regions and distributing industries across states. The results have been discouraging as these measures increased inefficiency and hampered effective industrial growth. The more advanced states have been better placed to benefit from liberalisation, with well-developed infrastructure and an educated and skilled workforce, which attract the manufacturing and service sectors. Governments of less-advanced states have tried to reduce disparities by offering tax holidays and cheap land, and focused on sectors like tourism which can develop faster than other sectors. India's income Gini coefficient is 33.9, according to the United Nations Development Program (UNDP), indicating overall income distribution to be more uniform than East Asia, Latin America and Africa.
For a person working for a wage, their source of income is their job, or their labor (aka their time that they sell to someone). But you can own a house, and rent it out, and when your renters pay you renter every month, the source of that income check is your rental property, or your house. It would just be called rental income. If you have money in the bank in an account that pays interest, those interest payments are another source of income. We can say the source is interest payments, or we can identify the asset that is generating rent, and say your money in the bank that is generating “rent” (aka interest) is your source of income.