Documents to keep on house property sale?

On closing the deal on selling my house property, what documents should I keep regarding the transaction? Should they be originals and certified or are photocopies OK? The implications I am looking are as proof for tax filing as well as proof of transaction. Do I need some document on what all cheques were received.

Would the property dealer provide these documents automatically or I need to ask for them.
This question is specific to Indian context around Noida.