For regional stories like this, the best bet is often the publisher's own website or app. If Srikala published it through a magazine like 'Kumudam' or 'Malai Malar', their digital editions would be the legal source. It's worth checking if those publications have official e-magazine subscriptions.
You know, it's wild how hard it can be to find these older books online. I tried looking for it last year after my grandma mentioned it, and I hit a total dead end on all the usual ebook stores.
I even checked a few of those Indian online book marketplaces that sometimes have PDFs, but they looked super sketchy and I wouldn't trust them. It's a real bummer because I prefer reading on my tablet.
Maybe the rights are tangled up? That happens a lot with older works. Unless there's a renewed interest or a TV adaptation, I wouldn't hold my breath for an official release anytime soon.
The pacing of this search is going to be slow. You won't find it in five minutes. You'll open a dozen tabs, follow dead ends, and maybe come back empty-handed today. But bookmark your searches and check back in a month. Sometimes listings appear out of nowhere when a publisher finally gets around to digitizing a back catalog.
It's a bit depressing, honestly. Such a monumental work, trapped in a single format. The digital world is passing it by because the gatekeepers haven't opened that particular gate. There's no conspiracy, just inertia and a different set of market calculations. So, to answer your question directly: based on all available commercial and bibliographic data, an authorized PDF edition of 'Kannan Varuvano' has not been published. Any PDFs in the wild are fan-created or pirate-created, not publisher-created. To experience the novel as the author and publisher intended, you need the physical object. Consider it a chance to unplug and enjoy a masterpiece in its original form.
Kobo's ecosystem is another avenue. Their store is decent and they partner with local bookstores in some regions. While their catalog skews Western, they might have partnerships with publishers carrying this title.