cannot copy boot.efi on the selected drive

Hey

I bought an SSD for my macbook pro(mid-2012) .Now when I am trying to clean install os x EL Capitan it's giving an error saying that OS X cannot be installed on this disk.The SSD is (http://www.amazon.in/Transcend-256GB-External-Solid-State/dp/B00VX82P38?ie=UTF8& psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00).

I also tried cloning software at the end of the process its giving error boot.efi cannot be copied on the selected drive.

Please help.