May I ask for some clarification, namely, is this the question about (1) Roman law prior to the Twelve tables, and on that further, what were the possible religious and ritualistic influences, and their significance? Or is this a matter of (2) classical & Republican, (3) post-classical ( or imperial ) law, (4) Byzantine, or later, say (5) medieval developments? The answers would very much differ.

Pending the response on which to say more, an overview of the issue if (1);

Bell, S., & Du Plessis, P. (Eds.). (2020). Roman Law before the Twelve Tables: An Interdisciplinary Approach. Edinburgh University Press.

Alan Watson, (1992) The state, law, and religion: pagan Rome. University of Georgia Press.