Every country including India mutilates and remanufactures their high school history books.
Remember! High school education CANNOT be all encompassing education.
We all should know that the first 10-12 grades prepare you HOW to read and write.
Yes every country does that. I have never taken a effort to learn history by myself, but i have read enough to notice how the text book interpretations of Indian history changes from a Congress govt to a BJP govt. This is enough to guess that neither is presenting a complete picture.