How to divide property between siblings?

My mother in law was absolute owner of two independent houses in Bengaluru. she passed away 15 years ago. She had three children ie one son (unmarried) and two daughters. The son i.e., my brother-in-law has changed the Khata in the office of city corporation of Bengaluru and got his name as owner of two houses after taking some signatures from his two sisters. No change has been made in the Sub-registrar office. he is enjoying the rent and also paying the taxes. tax is not much when compared to rent what he is getting. He is not showing any interest at all in sharing the property. now whether both sisters can get some share in the property? if yes what is the procedures to be followed?