Father gifting house to maid — can we stop it?

We own a house in Chennai that was built with funds from both my mother and father’s joint account. After my mother passed away in 2018, my father became abusive and started an affair with our maid. Although my brother and I contributed financially, the house is in my father’s name. Now he wants to gift the house to the maid. What legal steps can we take to claim our rights in the property?