India has one of the largest refineries in the world at Jamnagar run by Reliance Ltd. It buys 2 million barrels a day of oil from Russia, making up a third of Russian oil exports and second only to China which takes in half of Russian oil exports. India buys this at about $60 a barrel and it generates about $45 billion dollars of revenue for Russia. Indian refineries have the technology to process Russia's heavier crude oil. Some of it is processed in India and exported to Europe.
US and DJT statements about India and a tariff rate of 25% are based on India moving from exporting less than 2% from Russia in 2021 to 45% of its imports in 2024.