Transfer Of Father's Property , He Died Recently

My father passed away at the age of 67 in the year 2018 ( 13-jul-2018) due to sudden BP. And my mother is alive. She is 60 yrs old now. I am the only son , I have 1 baby girl , got married to a doctor in the year 2015 ..I am into 38 years old now. My only elder sister , who got married in the year 2011, did not have kids. My father has not made any will. Kindly let me know whether myself and mother are only the legal heirs for the property or my sister can claim their share and whether my mother can make a will giving share to my elder sister. Your advise help us in knowing the rights of individual