In plain words
Behold the Adityas, Vasus, Rudras, Ashvins, and Maruts. Behold many wonders never seen before, Bharata.
Word for word
Behold the Ādityas, the Vasus, the Rudras, the two Aśvins, the Maruts; likewise behold many marvels never seen before, O Bhārata.
The commentators
Bhagavadgītābhāṣyam· bhāṣya
पश्य आदित्यान् द्वादश, वसून् अष्टौ, रुद्रान् एकादश, अश्विनौ द्वौ, मरुतः सप्त सप्त गणाः ये तान् । तथा च बहूनि अन्यान्यपि अदृष्टपूर्वाणि मनुष्यलोके त्वया, त्वत्तः अन्येन वा केनचित् , पश्य आश्चर्याणि अद्भुतानि भारत ॥ ६ ॥
In plain words
Look: the twelve Ādityas. The eight Vasus. The eleven Rudras. The two Aśvins. And the Maruts, ranked in troops of seven upon seven — look at them. And many more besides, that no one in the human world has ever laid eyes on, not you, not anyone else at all. Look at the wonders, the sheer marvels, Bhārata.
Close to the Sanskrit
See the Ādityas, twelve; the Vasus, eight; the Rudras, eleven; the Aśvins, two; the Maruts — those which are groups of seven and seven — see them. And likewise many others too, never seen before in the human world by you, or by any other than you — see the wonders, the marvels, O Bhārata.