The work has to start from Government side. Where is the EV related policy? What are the goal posts? What is the infrastructure that the government will be putting up in the next 5 years at least? What is the policy regarding EV battery usage and disposal? What are the import terms for batteries and drive trains in short run ? You don’t expect the industry to develop expertise in EV and start completely Made in India EVs in short term , do you? Where are the Public Private Partnership deals? Unless the Government seriously starts taking steps, the industry will just make sporadic efforts , and you can’t blame them. If push comes to shove, car manufacturers will import from China and assemble in India- it will still work out cheaper for them than putting up all new manufacturing plants.
State Governments too will ensure that ICE reigns, as after GST, large chunk of revenue comes only from taxing gasoline. Who knows , if by some miracle, the Government changes, the whole EV policy will be shelved. Weighed against these uncertainties, you can’t blame the companies for being cautious with heavy EV investment