Crude oil price is decreasing in the international market. But in India, the price of petrol and diesel is gradually increasing. Why?
To repeat EnergyNumbers's comment as an answer to this question, the following chart from the St Louis Federal Reserve shows the increase in the crude oil price in US Dollars in the first half of 2016.
Other factors also affect local diesel and gasoline prices and timings, but this increase will have contributed to the local change.