"Those who are free from anger and all material desires, who are self-realized, self-disciplined and conquering the mind find atman sukham very near."
Brahma = atman, nirvanam = happiness [ atman anubhavam of a Karma yogi], abhito = very near, vartate = is available. Person who has got atman sakshatkaram, finds atman sukham or happiness close by. Sri Krishna has shown the 6 steps in the slokas 20 to 25. Kama = lust, krodha = anger, vimuktanam = discarded, yatinam= yati or sanyasi or he who has abandoned any attachment to woldly desires and finds only God as all for him, cetas = mind, yata = directed only in the atman. Once he has abandoned all worldly desires, it does not mean the mind is blank. Mind is also an organ and it has to be deployed. So, after stopping his mind from all worldly desires, the mind is directed to view atman. Viditatmanam = therefore, conquering his mind, for him the atman anubhavam is just close by. Mind is powerful and it has no limits, unlike other external organs like hands or mouth. To conquer a mind, we require something which is superior. Atman is able to do that. Mind as such has no gyana or intellect. Mind is not eternal. Such limitations are not there for atman and so mind is conquered by atman, once mind is directed to concentrate on atman. With that he abandons kama and krodha, detached from worldly desires, mind concentrated on atman, he conquers mind and finds happiness of atman anubhavem at close by. The six steps mentoned in the slokas from20 to 25, are mentioned in the four words in this sloka- kama krodha vimukhtanam, yatinam, yata chetasam and viditatmanam. Steps mentioned are: 1] unaffected by likes and dislikes 2] unaffected by worldly desires 3] realizing the defects in the worldly pleasures 4] conquering kama and krodha before atman casts off the body 5] atman alone is regarded as bhogyam, bhogasthanam and bhogopakaranam and 6] seeks to help all living beings in their hour of need. Person whio has come on all these steps finds atman sukham or happiness at hand's reach.