Marx's analysis of the Indian situation upto the middle of the 19th turns on three factors,
1. The destrutive role of the British in in India, uprooting the old society,
2. The regenerative role of the British rule in India in the period of free-trade capitalism, laying down the material premises for the future new society,
3. The cosequent practical conclusion of the necessity of a political transformation whereby the Indian people should free themselves from Imperialist rule in order to build the new society.
"The English millocracy intend to endow India with railways with the exclusive view of extracting at dimished expenses the cotton and other raw materials for theiir manufactures. But when you have once introduced machinery into the locomotion of a country, which posses coal and iron , you are unable to withhold it from the fabrication. You cannot maintain a net of railways over an an immense country without introducing all those industrial processes necessary to meet the immediate and current wants of railway locomotions, and out of which there must grow the application of machinery to those branches of industry not immediately connected with railways. The raiway system will therefore become, in India, trulythe forerunner of modern industry. resulting from the railway system, will dissolve the hereditary divisions of labour, upon which rest the Indian caste castes, those decisive impediments to indian progress and Indian power." (Marx, The future results of Bitish rule in India, NY daily Tribune, aug 8, 1853).
Imperialism was laying down the material conditions of new advance. But that new advance could only be realised by the Indian people themselves on conditions that they won liberation from Imperialist rule, either by their own successful revolt , or by the victory of the working class in Britain, carrying with it the liberation of the Indian people. Until then, all material achievements of imperialism in India could bring no benefit or improvement of conditions to the indian people.