Not only read, make sure your lawyer goes through it in detail.
"It is also agreed by the PURCHASER that in the event of pre-closure of the loan by the client, he shall not collect the sale deed deposited with the financial institutions for creating mortgage without written permission from the BUILDERS/VENDORS".
Make sure you understand what clause is this. Ask them to delete it and they will not agree. Ask them for an explanation, and see if you can buy the explanation provided by them for retaining this clause in the agreement