Linux holds a market share of approximately 14% in India.
I'm not sure how accurate StatCounter is, given that most Linux users use adblockers. However, according to it, Linux has almost a 14% desktop share in India.
I would assume that “market share” is related to the relative number of units sold/number of active subscriptions/fraction of total sales in terms in revenue, or some similar metric. I run a variety of different distributions on servers (bare metal, VMs and containers) and desktop computers. Do they all count equally? Without giving it more thought, I wouldn’t even know how to determine the market share of Ubuntu in my own home in a sensible way.
With Windows, I can just count the number of active licenses. Oh wait, its zero.
For once, Redhat and Suse do have market share, because they are companies. Other distros not so much. Then the reliability of the numbers, since you can only guess it from downloads and useragents.