On 18. Jul 2022, at 7.56, Nagaraj Paturi via INDOLOGY <indology@list.indology.info> wrote:

Quotes like सतां हि सन्देहपदेषु वस्तुषु प्रमाणमन्तःकरणप्रव्रुत्तयः indicate words like अन्तःकरण and  अन्तःकरणप्रवृत्तयः as words close in meaning to conscience in classical works.

In most contemporary Indian languages, Sanskrit borrowings like अन्तःकरण , अंतरात्म(न्‌) is used in this sense.

In Tamil, the word manassaaklshin is found used, which can be guessed to have some Sanskrit source.