It is be;ieved that Bharat’s Natyashastra is the first work that discusses the form of Rasa process. However, as per to Dr GT Deshpande, before Bharata, two Acharyas Druhin and Vasuki also proponded two different Rasa traditions. Bharata restricts himself to the Rasas in Drama.
His rules of Rasa is as follows: A combination of Vibhaava, Anubhaava and Sanchaari Bhaava leads to the formation of Rasa just as the different tastes like bitter, spicy, sour, sweet etc produce tasty food. Rasa is the central principle of Indian dramatics and poetics. Rasat-et-Ras- that can be tasted in Rasa. There six kinds of Rasa- bitter, spicy, acrid, sweet, salty, sour.
These Rasa can only be experienced bythe sense of taste. The food that is made up of all these Rasas is called the six-rasa-food. The same idea of taste is applied to drama and poetry. The form of Rasa- Rasa is tased. On this point there is agreement. There is however a difference in that some argues that the taste is experienced whereas others argues that it is consumptions. Abhinava Gupta argues that this experience is continuous one without any obstacle and is earthy and not otherworldly. Some however argue that the Rasa experience is similar to the spiritual experience or Brahmasvaada. A Rasa is the urbanized realisable state of a everlasting mood, which is called Sthayi Bhava. This expansion towards a realisable state grades by the interplay on it of helper emotional conditions which are called Vibhavas, Anubhavas and Sanchari Bhavas. Vibhavas means Karana or cause: it is of two kinds - Alambana, the personal or human object and substratum, and Uddipana, the excitants. Anubhava, as the name signifies, means the ensuants or effects following the rise of the emotion. Sanchari Bhavas are those crossing feelings which are secondary to an everlasting mood. The effect of Rasa (रसपरिणाम) – According to Abhinava Gupta, Rasa leads only to Sukha. According to Ramachandra Gunachandra, the author of Natyadarpan, Shringar, Hasya, Veera, Adbhuta and Shanta Rasas lead to happiness while Karun, Bhayanak, Beebhatsa and Raudra lead to sorrow and the Rasik is attracted to both, especially a good mix of both.