In plain words
The seven great seers and the four Manus of old were born from My mind, their thoughts set on Me; from them came these creatures in the world.
Word for word
The great seers, seven, of old, [and] the four Manus likewise, whose thought is on Me, mind-born, were born [from Me]; of whom in the world [are] these creatures.
The commentators
Bhagavadgītābhāṣyam
किञ्च —
महर्षयः सप्त भृग्वादयः पूर्वे अतीतकालसम्बन्धिनः, चत्वारः मनवः तथा सावर्णा इति प्रसिद्धाः, ते च मद्भावाः मद्गतभावनाः वैष्णवेन सामर्थ्येन उपेताः, मानसाः मनसैव उत्पादिताः मया जाताः उत्पन्नाः, येषां मनूनां महर्षीणां च सृष्टिः लोके इमाः स्थावरजङ्गमलक्षणाः प्रजाः ॥ ६ ॥
In plain words
And there is more —
The seven great seers — Bhṛgu and the others — are the earlier ones: they belong to an age already gone. The four Manus are the ones everyone knows as the Sāvarṇas. And they are madbhāvāḥ: their whole contemplation rests on me. They carry Viṣṇu's own power. They are mānasāḥ: made by mind alone. Born from me, which is to say, come forth from me. And these creatures here in the world, everything that stands still and everything that moves — that is what those Manus and those seers brought forth.
Close to the Sanskrit
Moreover —
The seven great seers, beginning with Bhṛgu, the former ones — that is, those belonging to a past time; the four Manus, likewise well known as the Sāvarṇas; and they, madbhāvāḥ, that is, ones whose contemplation is fixed on me, endowed with Viṣṇu's power; mānasāḥ, that is, produced by mind alone; born from me, that is, arisen; of which Manus and great seers the creation is these creatures in the world, marked as unmoving and moving.