Renunciation of result of action is Nishkama Karma..This is a Chapter of Knowledge by which one can attain Moksha. This yoga at First the Bhagavan preached it to Suryadeva(Sun). Surya deva preached it Vaivaswatha Manuvu. Then Vaivaswatha Manuvu preached it Ikshvak.From him Rishis got this Knowledge.