My co-founder is trying to oust me and take over the startup, what can I do?

I'm based in Bengaluru and co-founded a tech startup with a friend. Recently, I found out he changed all the company passwords and excluded me from important meetings. We have a founders' agreement but he seems to be violating it by trying to take over. I'm worried he might even change official documents to remove me. What legal steps can I take to protect my rights and interests in the company? Is there immediate legal action I can pursue to stop him?