B.G 6.02

यं संन्यासमिति प्राहुर्योगं तं विद्धि पाण्डव। न ह्यसंन्यस्तसङ्कल्पो योगी भवति कश्चन ॥२॥

yaṁ saṁnyāsamiti prāhuryogaṁ taṁ viddhi pāṇḍava। na hyasaṁnyastasaṅkalpo yogī bhavati kaścana ॥2॥

[यं संन्यासम् इति प्राहुः योगं तं विद्धि पाण्डव। न हि असंन्यस्त सङ्कल्पः योगी भवति कश्चन॥
यं (yaṁ) - That which; संन्यासम् (saṁnyāsam) - renunciation; इति (iti) - thus; प्राहुः (prāhuḥ) - they say; योगं (yogaṁ) - yoga; तं (taṁ) - that; विद्धि (viddhi) - know; पाण्डव (pāṇḍava) - O Arjuna; न (na) - not; हि (hi) - indeed; असंन्यस्त (asaṁnyasta) - unrenounced; सङ्कल्पः (saṅkalpaḥ) - wordly intentions; योगी (yogī) - yogi; भवति (bhavati) - becomes; कश्चन (kaścana) - anyone.]

O Arjuna, know that which they call renunciation as Yōga. For sure, no one becomes a Yōgi who has not renounced worldly intentions.

Gīta Tātparya 6.02

The renunciation is indeed a special aspect of Yōga.

योगविशेष एव संन्यास इत्यर्थः ॥२॥

yogaviśeṣa eva saṁnyāsa ityarthaḥ ॥2॥

[योगविशेष (yogaviśeṣa) - the particular aspect of yoga; एव (eva) - indeed; संन्यास (saṁnyāsa) - renunciation; इति (iti) - thus; अर्थः (arthaḥ) - meaning;]

The renunciation is indeed a special aspect of Yōga.