1. Rapidly Rising Population:

The population during the last 45 years has increased at the rate of 2.2% per annum. On average 17 million people are added every year to its population which raises the demand for consumption goods considerably.

2. Low Productivity in Agriculture:

The level of productivity in agriculture is low due to subdivided and fragmented holdings, lack of capital, use of traditional methods of cultivation, illiteracy etc. This is the main cause of poverty in the country.

3. Under Utilized Resources:

The existence of under employment and disguised unemployment of human resources and under utilization of resources has resulted in low production in agricultural sector. This brought a down fall in their standard of living.

There are many reasons for the poverty in India.Some of them are :-
*Historical causes : During Colonialisation, the british ruined traditional handicrafts and discouraged development of industries like textiles which resulted in less number of jobs i.e increase in poverty.
*The effects of Green Revolution were limited to only some parts of India like Punjab and Harayana
*It is also because of huge income inequalities. One of the major reasons for this is the unequal distribution of land and other resources.
Hope it helps and pls mark as the best answer. :-)