The scales of Raga Ravichandrika are as follows :

Aarohanam (Ascending) : S R2 G3 M1 D2 N2 D2 S’
Avarohanam (Descending) : S’ N2 D2 M1 G3 R2 S

This raga is a Janya Raga, derived from Harikambhoji (below), 28th on the Melakarta scale. Note the vakra sanchara in the Arohanam.

28 Harikambhoji

Though Ravichandrika is well known thanks to the by two gems by Tyagaraja, Makelara and Nirvadhi Sukhada, it is rather a rare raga. Muthiah Bhagavathar’s Sarvjna  Sambasahasaksha is also in Ravichandrika. This raga seems to be sung mostly in the early stages of concerts. There exists a rare raga in Hindustani music also called Ravichandrika where, unlike the Carnatic equivalent, tIvra nI is used in the avarohana. The Hindustani raga Rageshri also closely resembles Carnatic Ravichandrika. Charumathi Raghuram plays both Rageshri and Ravichandrika in this recording so you can compare the two.

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.