Harish Khanolkar 30 January 2022
P. Venu (Advocate) 31 January 2022
The facts, as posted, lack clarity. Anyhow, you may be file a suit for partition. Entries in revenue records (7/12 mutations) do not create or extinguish title to property.
Aryan Raj 31 January 2022
To add a name to the 7/12 paperwork, go to the Tehsildar office that has jurisdiction and apply for your name to be entered. He/she must include a copy of the sale deed. The 7/12 mutation entry will be made in the applicant's name, and then the rest of the procedure will be followed; hence, adding your aunt's name to it after her death appears to be illegal.
They will get the property share accordingly as mentioned in the Hindu Succession Act. And to answer your 3rd question I will have to ask you for a better explanation about your doubt because your query is unclear.