Once you purchase a vacant site for construction of a structure on it of your choice subsequently, then you become the owner of the property by the virtue of the registered sale deed on your name.
If you are considered as an absolute owner of the property with clear and marketable title then there is no reason that the revenue department will not transfer the land revenue records to your name.
You may first of all confirm that if the landed property you intend to buy is a freehold property or leasehold property.
If it is a leasehold property then you cannot get the 7/12 records transferred to your name as an absolute owner of the property purchase by you.
In this situation it is advisable to not to buy the property without knowing the proper details of the property or without obtaining a proper legal opinion from a local lawyer on this regard.