Word for word:
asakta-buddhih — having unattached intelligence; sarvatra — everywhere; jita-atma — having control of the mind; vigata-sprhah — without material desires; naiskarmya-siddhim — the perfection of nonreaction; paramam — supreme; sannyasena — by the renounced order of life; adhigacchati — one attains.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
One who is self-controlled and unattached and who disregards all material enjoyments can obtain, by practice of renunciation, the highest perfect stage of freedom from reaction.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Real renunciation means that one should always think himself part and parcel of the Supreme Lord and therefore think that he has no right to enjoy the results of his work. Since he is part and parcel of the Supreme Lord, the results of his work must be enjoyed by the Supreme Lord. This is actually Krishna consciousness. The person acting in Krishna consciousness is really a sannyasi, one in the renounced order of life. By such a mentality, one is satisﬁed because he is actually acting for the Supreme. Thus he is not attached to anything material; he becomes accustomed to not taking pleasure in anything beyond the transcendental happiness derived from the service of the Lord. A sannyasi is supposed to be free from the reactions of his past activities, but a person who is in Krishna consciousness automatically attains this perfection without even accepting the so-called order of renunciation. This state of mind is called yogarudha, or the perfectional stage of yoga. As conﬁrmed in the Third Chapter, yas tv atma-ratir eva syat: one who is satisﬁed in himself has no fear of any kind of reaction from his activity.