The book was usefull if you want an introduction to indian music theory and better understand the bases.
It was mostly theory, different raags, introduction to the sargam (do re mi) not a lot was about playing the bansuri in itself. There was a little bit too much secondary informations for me, like other indian wind instruments, famous players...
Now about the informations in the book, there was some times when i was a little bit doubtful on the quality of the information. I read it a while ago but for example in the chapter on the different types of bansuri it didn't mention the E bansuri in the types of bansuris availables even if E bansuris seem to be the most used in classical indian music.
There was also this part where it was written that "one bansuri cannot be used for producing different octave notes" but from what i saw you can definitly play more than one octave on the bansuri.
Some parts of the book can be contradicting, but its relatively rare.
The phrasing and the english was sometimes weird, i'm not a native english speaker but it seemed there were some mistakes here and there that can make the reading a little bit harder to understand.
In the end it was still a nice introduction to indian music and the bases of raaga where explained in an easy to understand manner even for someone really new to solfège like me.