As we all know back in the past there existed many different śākhās ("branches" or "recensions") of various Vedas. For example, in the case of the Rigveda, the pariśiṣṭa ("supplement") of the Yajurveda mentions five śākhās of the Rigveda, these are Śākala, Bāṣkala, Aśvalāyana, Śaṅkhāyana and Māṇḍukāyana. Meanwhile the pariśiṣṭa of the Atharvaveda lists seven śākhās and according to Patanjali there were twenty one, although the last number reflects the number of schools that taught the Rigveda, not the number of recensions of the Rigveda.[1] As of today, only two śākhās are extant, these would be the Śākala and the Bāṣkala, and of these two only the Śākala has survived in its entirety.[2]
Now a widely held belief among Hindus is that the Vedas are the source of dharma, an important concept in Hinduism which instructs us about how we are supposed to conduct ourselves, differentiate between righteous and unrighteous action, know what is beneficial for us and what is not, and so on.[3] And yet not only are the Vedas not fully extant but they also exist in different recensions. And while some parts of two recensions can be nearly identical, other parts can be entirely different from one another. For example in case of the Śākala and Bāṣkala recensions of the Rigveda, the Samhitas of both recensions are nearly the same but the Upanishads are completely different.[4]
So are we supposed to regard all the different recensions as the source of dharma, or is a particular recension the true source of dharma and the others are not?
Sources:
[1] Stephanie W. Jamison, Joel P. Brereton, The Rigveda: The Earliest Religious Poetry of India (2014), Oxford University Press, pg 16
[2] Sures Chandra Banerji, A Companion To Sanskrit Literature Second Edition (1989), Motilal Banarsidass, pg 300–301
[3] Grimes, John A, A Concise Dictionary of Indian Philosophy (1996), State University of New York Press, pg 113
[4] CG Kashikar, Rig Veda Mantra Samhita Part V (2018), Sri Aurobindo Kapali Sastry Institute of Vedic Culture, Preface