I've spent countless hours researching this and I thought I'd share what I found in case anyone comes to this page in the future. Plus it allows me to collect my thoughts. I'm just learning so it's possible (probable) that I say something incorrect, if so, please forgive me.
Bollywood type music: Has nice melodies like hindustani but has chord progressions and harmony like Western music.
Hindustani Classical Music:
Is based on scales (modes) and the music is improvised. Performances can last up to 1 hour just improvising on the scale. there are no chords. The melody is sung or played on a melody instrument such as the bansuri flute (or harmonium or sitar). The bansuri is very similar to the whistle. It has the same fingerings. The Indian scale starts on Sa which would be a G on a D flute/whistle. So they call the flute a 'G' where we call it a D. Bansuri is in just intonation so some notes sound a bit different but I haven't found the difference to be huge except maybe on C#. I'm debating if I want to purchase a bansuri or just play the whistle. One world trading has good bansuris, one in the key of D is about $125. A cheapie that may not be as well in tune, is around $60. The accompaniment is with a drone, the tampura and tabla. There are 74 main ragas (modes/scales) that are played. I'm starting with Raga Yaman which is often used for beginners.
I had to learn the Indian solfege system and that came pretty easy just associating each note with a note on the whistle. "Sa" is the tonic (like Do) and is the "G" note on the whistle (on a D whistle).
Next I started learning to play along with a recording I found at this website. It's the best I've found. He covers the scale, ornaments, and then gives the music for two raga compositions. He plays on a key of Low B flute, which is the common key for this music but the flutes are huge (like playing a Low B whistle). so I pitch adjust the mp3's 1 pitch lower to Bb and I play it on my Bb whistle. Or one could pitch adjust it up 3 semitones to play it on D.http://www.flutebansuri.com/ragas/yaman
So that's where I'm at. I find it fun and peaceful, very meditative. This is totally different than ITM so for me it's just for a change. I still play ITM more though.