The scales of Raga Hamsanandi are as follows :
Aarohanam (Ascending) : S R1 G3 M2 D2 N3 S’
Avarohanam (Descending) : S’ N3 D2 M2 G3 R1 S
Hamsanandi is a janya raga, derived from Gamanashrama which is 53rd on the Melakarta scale.
It is comparatively a new-comer to Carnatic Music. It is close to Sohni in Hindustani Music (Sohni does not have R1 in Aarohanam though). A joyful raga, it is suitable to be sung in evenings. Srinivasa Tiruvenkata Ramana by Papanasam Sivan, Punnagai Ondre Podume by Ambujam Krishna and Pahi Jagajjanani by Swati Tirunal are some well know compositions in this raga.
Tamil speakers may be interested in watching this episode of Isai Payanam by Charulata Mani.
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) are a very important part of a raga.