I am staying in a rented apatments, I want to avial a loan so they asking for address proof tell me how to write a agreement for address proof form the apatment owner

If you signed a rental agreement/lease, that should be sufficient.

iam staying in a rented apatments, i want to avial a loan so they asking for address proof tell me how to write a agreement for address proof form the apatment owner
The bank will ask you the name, address and telephone number of your landlord. Give it to them. They will ask you for a copy of your lease. Give it to them. The loan processor from the bank will call the landlord to verify the lease. He will ask if you have ever paid late, whether you are currently on time with your payments, how much you pay in rent and approximately how much you pay in utilities. The landlord will be faxed a form to fill in and return to the bank. As a manager, I can tell you we do it all the time. No problem.