Who told you that OPEC countries are not selling oil to India directly. These are all your imaginations... and India is getting the oil from most of the OPEC countries and in a better rate than many other countries... The daily prices are available in NYMEX and various commodity exchanges and you can also buy oil from any trading platforms...
The Nuclear deal is nothing to do with the petrol prices. Most of our neighbouring countries inclding China, Singapore, Malaysia and Indonesia have already raised the fuel prices in the range of 30 to 50 %.
