असंयतात्मना योगो दुष्प्राप इति मे मतिः। वश्यात्मना तु यतता शक्योऽवाप्तुमुपायतः
asaṅyatātmanā yogo duṣhprāpa iti me matiḥ vaśhyātmanā tu yatatā śhakyo ’vāptum upāyataḥ
It is not possible to attain Self-Realization unless one knows how to control oneself; however, for one who, striving by the proper means, learns such control, it is possible.
Translated by Shri Purohit Swami
I think Yoga is hard to be attained by one with an uncontrolled self, but the self-controlled and striving one can attain it by the appropriate means.
Translated by Swami Sivananda
Word meanings (from the gita/gita dataset)
asanyata-ātmanā—one whose mind is unbridled; yogaḥ—Yog; duṣhprāpaḥ—difficult to attain; iti—thus; me—my; matiḥ—opinion; vaśhya-ātmanā—by one whose mind is controlled; tu—but; yatatā—one who strives; śhakyaḥ—possible; avāptum—to achieve; upāyataḥ—by right means