B.G 6.15

युञ्जन्नेवं सदात्मानं योगी नियतमानसः। शान्तिं निर्वाणपरमां मत्संस्थामधिगच्छति ॥१५॥

yuñjannevaṁ sadātmānaṁ yogī niyatamānasaḥ। śāntiṁ nirvāṇaparamāṁ matsaṁsthāmadhigacchati ॥15॥

[युञ्जन् एवं सदा आत्मानं योगी नियत मानसः। शान्तिं निर्वाण परमां मत् संस्थाम् अधिगच्छति॥
युञ्जन् (yuñjan) - striving to be united; एवं (evaṁ) - thus; सदा (sadā) - always; आत्मानं (ātmānaṁ) - in the Lord within; योगी (yogī) - the yogi; नियत (niyata) - regulated; मानसः (mānasaḥ) - with, mind; शान्तिं (śāntiṁ) - peace; निर्वाण परमां (nirvāṇa paramāṁ) - after the abandonment of the body; मत् (mat) - in Me; संस्थाम् (saṁsthām) - abiding; अधिगच्छति (adhigacchati) - attains.]

The Yogi, thus with a regulated mind, always striving to be united with the lord within, having situated in Me, attains the peace up on departing the mortal body.

Gīta Bhāshya 6.15

'nirvāṇaparamāṁ' - up on departing the mortal body.

निर्वाणपरमां शरीरत्यागोत्तरकालीनाम् ॥१५॥

nirvāṇaparamāṁ śarīratyāgottarakālīnām ॥15॥

[निर्वाणपरमां (nirvāṇaparamāṁ) - the word 'nirvāṇaparamāṁ' means; शरीर (śarīra) - body; त्याग (tyāga) - abandonment; उत्तर (uttara) - after; काल (kāla) - time; इनाम् (inām) - of.]

The word 'nirvāṇaparamāṁ' means 'up on departing the mortal body'.