If you possess a sale deed for land purchased 40 years ago and have been in continuous possession, you may still be able to register it. While direct registration might be difficult if sellers are deceased, you can file a suit for declaration based on long adverse possession. Alternatively, approach the local SRO office with all documents and an affidavit to request adjudication of the agreement, potentially paying stamp duty, registration fees, and any penalties. Seeking advice from a local property lawyer is recommended.