It seems sanctions against companies of India, Turkey and China are now reducing Russian oil sales with more to follow shortly.
India has bought Russian oil to manufacture products for resale to the West at the expense of Ukraine.
Before the war, India did not buy any significant amount of Russian oil. Within 2 years, they became Russia's top customer.
So the West is saying we will not buy your oil-based products if they originate from Russia. It defeats the purpose of buying Russian oil if they have no one to sell the products to.
Sure they must have domestic needs as well - but it seems India were benefitting more from the resale of oul than domestic consumption.