How can I get my share

My deasesed father's property will be divided in three shares as we are muslim Mom -1/8 After my mom's share Me-2/3 My sister-1/3 My sister is divorced and she stays with my mom. And I stay quite far from there.She knows very well I will be getting 2/3 and thats why she does not want to divide the property and as per her mom will be taking care of all the property of my father.And my mom is very innocent and she controls my mom and my sister wants to control indirectly all the property and want to collect all the rent by my mother's name.so that she does not want to divide and thats why she is saying after my father death mom will be taking care of everything.And she wants me to deprive to take rent and take my shares.All the property was in my father name.Though she is staying with my mom all the documents are with her. Now what should I do? If documents of property is with her then will I face any problem? And how can I get my share? Can she cheat me or I will get my share or not?