Word for word:
tat-buddhayah — those whose intelligence is always in the Supreme; tat-atmanah — those whose minds are always in the Supreme; tat-nisthah — those whose faith is only meant for the Supreme; tat-parayanah — who have completely taken shelter of Him; gacchanti — go; apunah-avrttim — to liberation; jñana — by knowledge; nirdhuta — cleansed; kalmasah — misgivings.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When one’s intelligence, mind, faith and refuge are all ﬁxed in the Supreme, then one becomes fully cleansed of misgivings through complete knowledge and thus proceeds straight on the path of liberation.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Transcendental Truth is Lord Krishna. The whole Bhagavad-gita centers around the declaration that Krishna is the Supreme Personality of Godhead. That is the version of all Vedic literature. Para-tattva means the Supreme Reality, who is understood by the knowers of the Supreme as Brahman, Paramatma and Bhagavan. Bhagavan, or the Supreme Personality of Godhead, is the last word in the Absolute. There is nothing more than that. The Lord says, mattah parataram nanyat kiñcid asti dhanañ-jaya. Impersonal Brahman is also supported by Krishna: brahmano hi pratisthaham. Therefore in all ways Krishna is the Supreme Reality. One whose mind, intelligence, faith and refuge are always in Krishna, or, in other words, one who is fully in Krishna consciousness, is undoubtedly washed clean of all misgivings and is in perfect knowledge in everything concerning transcendence. A Krishna conscious person can thoroughly understand that there is duality (simultaneous identity and individuality) in Krishna, and, equipped with such transcendental knowledge, one can make steady progress on the path of liberation.