Brother sold shared flat without my consent in Pune — what can I do?

My brother and I jointly inherited a flat in Pune from our parents. I recently discovered he sold the property without informing me or obtaining my consent. I trusted him completely and feel utterly betrayed. This happened two months ago, and he's avoiding my calls. I have no idea how to claim my rightful share or if I can reverse the sale. What legal steps can I take against him? Is there a way to secure my interest in this property?