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'm not sure adblockers change the OS they report. Other tools I know for a fact do it.
Edit: However, as @aebletrae@hexbear.net mentions, adblockers don't have to change what OS is reported to change the overall statistics. They explain how in a comment below.
I think the assumption is not that adblockers alter the user agent info, but that they also block other resources, so StatCounter won't see those users at all, leading to under-reporting.