Renunciation of action and the yoga of action both lead to the highest good. Of the two, though, the yoga of action is better than the renunciation of action.
Explanation
Arjuna has just asked which is better: giving up action (saṃnyāsa) or practicing yoga through action (karmayoga), which means acting while letting go of attachment to results. Krishna answers that both lead to liberation, the highest good (niḥśreyasa). He still rates karmayoga above renouncing action. Traditions differ on how close the two are: some see them as two routes to one goal, others see karmayoga as a preparation for renunciation.