Brother sold our Mumbai property without my consent, what are my options?

I just discovered that my brother sold our jointly inherited property in Mumbai without my approval. We inherited it from our parents and have equal share. I did not sign any documents or give my permission, but he managed to execute the sale. I'm in shock and feel utterly betrayed. What legal steps can I take to contest this sale and secure my rights? Do I file a case in the Mumbai courts immediately?