I expect when this was published that it was very helpful, but now the same information can be found online, with more thoroughness. Try https://www.sangtar.com/raagkosh/ I'd also recommend The Raga Guide: A Survey Of 74 Hindustani Ragas instead, as it comes with 4 CDs. This book starts off good, with each raga getting a fairly thorough treatment, but after a while he just puts the scale down, without the chalan, or typical shape of the melody. Go to Sangtar's website instead.