Property sharing between family members

Hi Sir/Mam My father has 1 son and 1 daughter, my father has died at the year of 1978,i am the eldest son I have taken care of my father borrowing as a eldest son in the family and have repaid all the my father lending and i dont have any document for that Some agricultural land are there on my father's name and last 40 years we did not do any agricultural activities in the land but after 40 years my sister demanding partition of the land. My questions are . 1. As i have take care of my father's borrowing , can i solely claim on the property? 2. If not then how much they have right and how it will be partitioned? 3. For me 3 children and my sister's have 2 children and can we divide the property as 5(Considering my sons and my sister's son ) share instead of considering 2 (Me and my sister) 4.My sister's sons are working in judical dept and police dept and they are saying they can easily win this because they are very close to the Judeges 5.Without my knowledge My sister