Right for fathers property

Hello, I have one property of house 40 X 30 sq feet build by my parents however my father was died in year 2002 leaving this property at that time my mother transferred this property to me via notary in year 2002.However she has fear whether I can sell this property therefore she never given me property papers. I was married in year 2010 and I am working in a multinational ,after my marriage my mother is insecure about this property whether this will be transferred to my wife in case any unfortunate event. Also There is another twist that my sister who has been divorced and she is leaving in the same house for almost 15 years with her son aged 20 now as of year 2019. My mother wants to sell this house into three partitions ,one for her,one for her daughter and one for me. also she is trying to again transfer this property in her name by the influence of her daughter. I have following questions: 1) As I was assured by my mother in year 2002 that this property is transferred to me by notary so this notarized agreement is suffice that I am owner of that property? 2) Who is actual owner of this property? 3) Can my mother transfer this property in her name without notifying me or any unlawful means? 4) Is my sister can also claim her right into this property? I am really confused and depressed for this situation,please guide me? Thanks Himanshu Dandle