Inheritance of property of my unmarried elder paternal aunt who died intestate

My grandfather wrote a Will and bequeathed his property in the form of a house and a small adjoining plot of land, among his 2 sons and 2 daughters. Both my grandfather and grandmother passed away. The 2 sons and 2 daughters too have expired. My grandparent's each of the 2 sons is survived by a son each and their younger daughter is survived by 2 daughters both of whom are married. My grandparent's elder daughter - our elder aunt - who never married and, therefore, had no children until her death on 7 April, 2022, died intestate. Now my question centers around the share of property of our elder aunt. Based on the last 15 years of search report from the registry office/court, we found she has not bequeathed her property her share of the house, to anyone. As per the above context I have 4 questions as mentioned hereunder - (I) Who will get her share of the property and in what way, I mean, documents like legal heir certificate or succession certificate? (II) What will be the proportion of the share? (III) Our deceased elder aunt's deceased youger sister's daughter who is married, came down from where she stays, to Kolkata, and performed elder aunt's final rights like the funeral, shraddh etc. For this will she get any special privilege over others in terms of inheritance of our elder aunt's share of the property? (IV) Since our elder aunt's demise, her share of property in the house is currently being occupied and used solely by the elder aunt's unmarried maternal uncle (everyone of us, the surviving heirs live elsewhere) who is now 90 years old, hard of hearing otherwise completely physically fit and financially extremely solvent, and who looked after her prior to her death. He is living in elder aunt's share of the property in the house without any written consent and or contract, but based on a verbal consent that was probably given to him by the elder aunt before her demise. He now says, as he took care of our elder aunt when she was alive, he will not move out despite he has his permanent residence in another part of Kolkata where he lived with his unmarried younger brother aged about 80 and physically fit, and a 24X7 maid for more than 30 years. Can I write a letter to him and urge him to either vacate the place and go back to his permanent residence or make his residential arrangements elsewhere, since we fear, he living in the house all alone, in case of any untoward incident happening, we may get dragged into problems. If possible kindly let me know your valuable opinions and suggestions. Thank you and regards.