The scales of Kamaas (alt spelling : Kamas, Khamas) are as follows :
Aarohanam (Ascending) : S M1 G3 M1 P D2 N2 S’
Avarohanam (Descending) : S’ N2 D2 P M1 G3 R2 S
It is a Janya raga, derived from Harikambhoji (see below), 28th of the Melakarta scale.
It’s origin is the Hindustani Kamaj Thaat. It is a late night raga and evokes the sringara rasa (love, beauty, attraction). A well loved raga, there are quite a few compositions which would be well known to the average listen like Brochevarevarura by Mysore Vasudevachar, Sitapati Na Manasuna and Sujana Jivana by Tyagaraja, Idadu padam Tookki by Papasanasam Sivan, the Varnam Mate Malayadwaja by Mutthiah Bhagavathar, and Sarasa Dala Nayana by Muthuswami Dikshithar. .
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.
Music To My Ears 
Is N3 used in khamas at times?
Yes Seetha, I understand N3 can be sparingly used as a ‘anya swara’. However, I am not a musician; these kind of questions are best addressed to more knowledgeable people.
Cheers. Suja
I was trying to play “brochevarevarura” (which is apparently fit to this raga), on the piano with N2 and N3. I could be wrong, but using N3 seemed to make it sound closer to the versions I listened to.
Hmmm….I am really not a musician and feel very reluctant to comment on questions like this. My very uneducated two-bits are that in my opinion, the piano does not catch the essence of ragas as there are no gamakas. My son sometimes plays carnatic ragas on the piano for me, and there are phrases which feel ok and phrases which feel very wrong. Secondly, N3 is sometimes introduced as a ‘anya swara’ so it does fit into the raga… Anyway, as I said, I am not qualified and it is best for you to talk to a teacher of C.M.
Cheers. Suja
N3 where it comes in swarjathi “sambasivayanave” notes… Please any one clarify the doubt
Hi Vasudha. You can use this link below:
http://www.shivkumar.org/music/varnams/sambasiva-swarajati.htm
Hope this helps.