Issue is that most of the modern smartphones have SoC (CPU + RAM + NVRAM + sometimes even GPU + Wireless all rolled into a single chip) without need of any 'interfacing chips'. I highly doubt you can fabricate any chips at feature size less than 90 nm required for any modern smartphone. For the record, neither can India.
I don't doubt that they may have SMT production lines, but for things like smarphone, it is usually much cheaper to buy ready made system boards with all things soldered. Buying components and putting together a mobo-design is much pricey. Unless you are doing a new custom phone, it is always cheaper to take a reference design, add few of your own peripherals and manufacture casing. Most of the input goes in customizing software. Heck if India and BD can focus on making a halfway decent UI running on stock devices, it will be a much bigger win. Remember, iPhone is great because its software fits its hardware really well and keeps user really happy.
For all their so called prowess Chinese phone makers have yet to make a great UX like iPhone and they only try copying it.
I once remember quite sometime back in 2010 or 2011 or so an India company called Notion Ink tried creating an India tablet around Nvidia's reference design. They bombed but their UX and device design was unique and really well thought of from ergonomics point of view.
https://en.wikipedia.org/wiki/Adam_tablet
https://techcrunch.com/2011/01/17/a-deep-look-at-the-notion-ink-adam-tablet-and-where-its-going/
They bombed because their rom was half baked and their update mechanism was broken so it bricked a lot of devices.