While the report does describe a dual boot device, it is not clear whether this would be a consumer dual boot device (i.e. choice of which platform to use at boot up), or the same device offered in two variants (one running Android and one running Windows Phone). The second scenario is more realistic, but it is likely that it would be possible for technically savvy users to swap between the two platforms by flashing new software (ROM) to the device.
This kind of device has become possible after Microsoft softened the hardware requirements for the Windows Phone platform. For example, Microsoft is now allowing on-screen navigation buttons, rather than physical / capacitive navigation buttons. This would allow Karbonn to re-use or multi-use devices developed for Android, such as the Titanium S5 Plus shown below right.
Karbonn's primary market is India, but it also sells devices in the Middle East and has announced its intention to expand sales operations to other markets. Its product portfolio is weighted towards the low end of the markets and it is anticipated that any Windows Phone product would fit in with that pattern. The most likely scenario is the production of a Snapdragon 400 based device, but it is also possible that the Karbonn could choose to take advantage of Windows Phone 8.1's support for the Snapdragon 200 SoC.
The Times of India quotes Sudhir Hasija, Karbonn's chairman, as saying that an agreement has been signed with Microsoft and that the company will launch a range of phones in about three months:
"Microsoft has eased the regulations and is opening up its platform for other players. We signed the agreement two days ago and will launch a range of Windows phones in about three months and will target office-going professionals and techies."
The reference to an agreement with Microsoft is likely reference to a finalisation agreement signed at MWC last week. Microsoft has been working with Karbonn (and other manufacturers), in conjunction with chipset maker Qualcomm, for the last six months in an efforts to build on the momentum established by Windows Phone in 2013, especially at the lower end of the market. The first fruits of this were announced at MWC, with further announcement coming in April (Windows Phone 8.1 unveiling at BUILD in April) and the early summer as manufacturers announce the first round of Windows Phone 8.1 devices.