The scales of Hindolam are as follows :
Aarohanam (Ascending) : S G2 M1 D1 N2 S’
Avarohanam (Descending) : S’ N2 D1 M1 G2 S
Hindolam is a janya raga, derived from Natabhairavi (below), 20th on the Melakarta scale.
Hindolam is pentatonic and symmetrical. This raga is normally played in the first half of a concert, before the ‘heavy’ ragas. I find it gentle, lyrical and poetic. There are a number of beautiful compositions in Hindolam. Samajavara Gamana by Tyagaraja, Mamavatu Sri Saraswati by Mysore Vasudevachar, Ma Ramanan by Papanasam Sivan and Samagana Lole by G.N.Balasubramaniam are all very well known songs.
Tamil readers may enjoy the following discussion on the raga by Charulatha 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.
Music To My Ears 
Grand explanation, very informative and helpful to theoretically novice enjoyers of classical carnatic music. Keep up the good work. Thanks
Thank you for your kind words 🙂
Great information. But can you please tell me how can we ornament arohanam and avarohanam in Hindolam
I’m sorry but I am not a music teacher, just someone who appreciates music. What you want to know is best taught by a teacher.
Cheers. Suja