The scales of Raga Nattakurinji are as follows :
Aarohanam (Ascending) : S R2 G3 M1 N2 D2 N2 P D2 N2 S’
Avarohanam (Descending) : S’ N2 D2 M1 G3 M1 P G3 R2 S
It is a Janya raga, derived from Harikambhoji which is 28th on the Melakarta Scale (see below).
This gentle raga which evokes devotion and compassion. Opinions differ as to the suitable times to sing this raga; some say daytime others say evenings. As this raga does suit elaborations, it is not unusual to see it chosen as one of the major pieces of a concert. Well known krithis in this raga Manasu Vishaya by Tyagaraja, Vazhi Maraithirukude by Gopalakrishna Bharati, Budham Ashrayami by Muthuswami Dikshithar, Mamava Sada Varade by Swati Tirunal and Paal Vadiyum Mugam by Oothukadu Venkata Subbaiyer.
Tamil speakers may enjoy this episode of Charulata Mani’s Isai Payanam program :
Note : The 12 notes in the octave are named as below. Please note that C is used as Sa for the sake of simplicity as the scale is relative in Carnatic Music. Also note that the scales paint only a superficial picture of the raga as the gamakas(ornamentations) and prayogas (signature phrases) are a very important part of a raga.
Music To My Ears 
Nattai kurunji varnam