A rasika is a term for an aesthete of Hindustani classical music. The term is derived from Sanskrit meaning full of Passion, elegant; with discrimination. Connoisseur - An expert able to appreciate a field; especially in the fine arts.
A rasika is a term for audience in Sinhalese
In the context of carnatic music
A rasika, in carnatic music terminology, is a person who has some knowledge of carnatic music and is able to appreciate carnatic music. In carnatic music concerts (or katcheri, as they are called), the audience is usually called rasikas.
References
Rasika Wikipedia(Text) CC BY-SA