It is called Nagābharanam in Muthuswami Dikshitar school of Carnatic music.
The mnemonic phrase is sa ri gu ma pa dhu nu.
[2] Its ārohaṇa-avarohaṇa structure (ascending and descending scale) is as follows (see swaras in Carnatic music for details on below notation and terms): (the scale uses the notes chathusruthi rishabham, antara gandharam, shuddha madhyamam, shatsruthi dhaivatham, kakali nishadham) As it is a melakarta rāgam, by definition it is a sampoorna rāgam (has all seven notes in ascending and descending scale).
A few compositions set to Naganandini are: This section covers the theoretical and scientific aspect of this rāgam.
Naganandini's notes when shifted using Graha bhedam, yields 2 other minor melakarta rāgams, namely, Bhavapriya and Vagadheeshwari.