As far as I know the ZF India, Hella, Robert Bosch etc provide transmissions, steering, fuel management, electrical, etc from their Indian factories. Some body parts are sourced from other Indian vendors.
Without the support of an advanced components industry such cars will be prohibitively expensive to import or meet the Indian homologation programme.
Unless the volume approaches about 20,000 cars per annum I don’t see how they can increase the deletion level and reduce cost further. Till then Indians will continue to buy the Merc as its more local since Indian manufacturing commenced in early 90’s.