The question is "If you invested Rs. 10 lakhs (1 million) in a project and expect to get a steady cash flow of Rs. 1 lakhs (100,000) every year over the next 5 years. What is the NPV of this project assuming prevailing interest rates of 15%?"

NPV tells you the current value of future cash flows and your initial investment in a project. In this case future cash flows are Rs.1 lakh every year for the netx 5 years and your initial investment is Rs.10 lakhs.

The 15% indicates what return you would have got if you had invested the money in other risk free investment options. So the question asks you what is the current value of these future cash flows + initial investment given the opportunity cost of 15%.
Formula is NPV = CF1/ (1+r)^1 + CF2/(1+r)^2 + .....+ CF5/(1+r)^5
Then subtract this from the initial investment of 10 lakhs.