The Jonpuri is the one that I cannot bring myself to quite grasp. Both Nagagandhari and Jonpuri being janya's of Natabhairavi with all notes present, it's confusing a bit.
vpadmana,
Nagagandhari is a nishad-antya janya raga of 20th mela NataBhairavi. In addition to this, 2 more different types of arohanam and avarohanam are also known to be existing to this raga, derived from different melas, viz. 23rd GM and 22nd Kharaharapriya.
1. Aroh: SRGMPDN Avaroh: NDPMGRSN of 20th Mela
2. Aroh: SRMPDNS Avaroh: SNDPMGRS of 23rd Mela
3. Aroh: NSRGMPDN Avaroh: NDPMGRSN of 22nd Mela
Nagagandhari raga is popular through the composition of Sri. M.Dikshitar ' sarasijanabha sodari sankari ' This raga also admits vakra arohana sanchara SRMGMPDNS . There is a song composed by Sri. Thyagaraja in this raga 'Oh rama rama '
The above given details are taken from Dr. S.Bhagyalakshmi's Ragas in Carnatic Music book.