My dad bought a property using his own money while living in a joint family. He registered it in his and my mom’s name. Is this property now considered joint family property under Hindu law?

No, the property is not automatically considered joint family property under Hindu Law. Since the property was purchased with your father’s individual funds and registered in his and your mother’s names, it is presumed to be their separate property. However, if there’s a specific agreement or intention to make it joint family property, that needs to be proven.