It's essentially a question of the network effects of infrastructure development. You need a combination of transport links, power (coal, or later on, hydro-electricity), and a large agricultural surplus. The only colonial power which really developed something approaching this where British in some parts of India, but the mindset of the Raj civil servants was very much opposed to such entrepreneurship.
This isn't set in stone, but I think you want a PoD that leads to the SS Great Eastern being a commercial success. The continued production of very large ships leads to the initial fall in average freight costs, the containerisation is developed for raw materials to exploit this. This leads some forward thinking industrialist to start the production of finished goods in India, to be closer to the raw materials, and it snowballs from there.
I can't see this being popular amongst the working man in the UK, but I don't think labour is yet organised enough to stop it. This process is likely to force the UK to re-industrialise. IOTL, the UK missed out on the second wave of the industrial revolution (chemicals etc), as the incremental benefits of moving into those industries and improving the quality and efficiency of the goods/production didn't make up for the capital investments of training the workforce and tearing down and replacing the factories. If those jobs are moving to India, then the industrialists will be forced to modernise and up-skill, as although the capital costs of doing so will be the same, the incremental benefit will be much higher, as their profitability will be collapsing.
It will probably take a generation, but the British will also benefit by having a significantly wealthier captive market of semi-skilled workers in India. This will mean that the rest of the Eastern empire will become more profitable as well, as the incentive for things like agricultural improvements will increase. All in all, a virtuous circle. The downside, of course, is nationalism, but even when that arises the fact that India is more economically integrated with the rest of the Empire will help.