Which documents are required to get a legal heir certificate

This is a case of inheritance, property is in delhi. The property is in the name of my father who expired. Now, we are one brother & one sister. My father did not leave any will. My sister is ready to relinquish her share. Based on below docs, can i get the legal heir certificate? 1) original death certificate of my father 2) ratio card stating siblings (me & my sister) 3) The original high court decree stating that my father is the owner 4) property tax 2017-18 (that is still in my father's name) 5) Electricity bill having my father's name, aadhar, PAN etc.