You have not mentioned the Nature of the Property.Befor Buying you have to Check the Following:
1) Nature opf the Land i.e it is Pakka Patta Land or Assgned Land.Also ensure that it this land is not attracting Land Celing.These you can ascertained from Revenue authorities and Sub-Registrar Office.
2) If it is Plot you should ensure whether it is in Authorised Laout Approved by Compitent Authority .
3) If it is Building ensure that the Construction is authorised.Also ensure that The Taxes are on whose name.Whether the Taxes are Paid up to Date.
4) After ensuring the above aspects obtain the Title Deed along with the Link Documents.Then obtain ECs at least for 30 Years and check them with the Link Documents you are having.After Satisfying the Same.You can Identify the Real owner of the Property by obtaining the ID Proof and Residence Proof
5) Finally get it verified with your Advocate in the Offices of the Sub-Registrar in which the Documents are Registered.
All the Above things your Advocate will Look after.