Sister sold our late father's house without my knowledge, what can I do?

I'm from Pune and recently discovered that my sister sold our father's house, which was supposed to be inherited by both of us. I had no idea about the sale until I came across the new owners. My sister handled everything without informing me, and I feel betrayed. I need to understand my legal standing here. Can I challenge the sale or claim my rightful share? What are the legal steps to address this betrayal?