you need to have a knowledge base (with your legal, or financial data) and use semantic search to feed the context for a model fine-tuned to follow instructions and answer from the context,
for small (7B) models there are OpenHermes-2.5-Mistral-7B, Mistral-7B-OpenOrca, dolphin-2.1-mistral-7b,
for bigger models there is Nous-Capybara-34B