The letter says, "you are hereby notified that your actions of uploading NCERT books on your site, is without permission from us and is a clear copyright violation. You may at best maintain a link to the books on the NCERT website after written permission."
In an interview in May, the founder Prashanth Ellina admits that the legality of his effort was not clear but he hopes things would work out with the educational bodies.
A few months back even I was thinking such a service ought to be built in India. Having a more liberal license for textbooks is a must. In Karnataka this year a severe mess up in textbook production has caused much trouble for school kids - the reason being government has banned private selling and instituted its own body to supply textbooks. I have heard of cases where students have written the first couple of tests without getting textbooks at all. Currently the High Court is looking into the issue:
"The schools said the State Government this year had constituted the Textbook Authority and decided to distribute textbooks to students from first to tenth standard through the authority. The State, it said, had decided against allowing sale of textbooks by private book-sellers."
Naturally many of these issues are being addressed in the US too. An old but good NYT op-ed says textbook prices rise at twice the inflation rate! Over there the problem is again copyright ownership but by various private publishers.
If the government is going to set the syllabus and provide education till secondary schools, can't they at least go for a Creative Commons kind of license? I am actually optimistic that this will happen soon.