Hello Aarsh,
After going through your query, I understand your concern regarding the notice by the original owner of the land. I am here to help you with the query.
First of all, I would like to tell you that it seems you have a strong side in the case as you have all the original documents (proving the lawful purchase of the property) regarding the property, and also you have possession of the property for 30-35 years.
The seller’s claim is now of no use if there was a legally valid sale with no government restrictions (such as being classified under B1 or similar categories) when the property was transferred to you. As per the provisions of the Transfer of Property Act, of 1882, once the sale is done, all the rights of the seller are dismissed over the property. This can be easily referred to the case of Vishwa Nath Sharma v. Shyam Shankar Goela (2007).
I can recommend you file a notice as a response to the notice attaching all the documents that are proof that you are the owner of the property (like receipts, sale deed, etc.). Additionally, you can also go with the option of filing a declaratory suit under Section 34 of the Specific Relief Act, 1963 asking for the declaration of your ownership to prevent any future implications.
At the same time, file an injunction application under Order 39, Rules 1 & 2 of CPC to stop the original owner from making baseless claims or creating a nuisance regarding your property.
I hope I was able to provide you with an answer to your query. If you need any follow-ups, please feel free to connect with me on LinkedIn. ( www.linkedin.com/in/pankhuri-rastogi-9221b2289 )
Thank You.