In the Muṇḍaka Upaniṣad (3.1.9) the situation of the soul in relation to prāṇa is explained:
eṣo ’ṇur ātmā cetasā veditavyo
yasmin prāṇaḥ pañcadhā saṁviveśa
prāṇaiś cittaṁ sarvam otaṁm prajānāṁ
yasmin viśuddhe vibhavaty eṣa ātmā
“The soul is atomic in size and can be perceived by perfect intelligence. This atomic soul is floating in the five kinds of air [prāṇa, apāna, vyāna, samāna and udāna]. The soul is situated within the heart, and it spreads its influence all over the body of the embodied living entities. When the soul is purified from the contamination of the five kinds of material air, its spiritual influence is exhibited.” Thus in the innumerable species of life the spiritual soul remains situated within prāṇa, or the material life air.
https://www.vedabase.com/en/sb/11/3/39
