This is a letter handed over by the developer to the customer stating that the property is complete and ready for occupation. This letter also indicates the final dues payable by the customer before the key is handed over to the customer.
So the builder makes sure that all the dues are clear from your side, but you as a customer must also go through a checklist before you accept the letter.
Now that you are sure about your house, you must also ensure that you have received all documents from the builder. Possession letter, No-Objection Certificate, Power of Attorney, Commencement Certificate, Search Report of the Builder’s Advocate, Receipts of payments made to the builder, Letter of allotment etc are some of the important documents required from the builder or developer during possession of the apartment.