When I connect Cloud devices here it seems on the reserve window that I m using but the device is not displaying also in device list it shows add a new device, but in reserve it shows device is connected
What version of Appium Studio are you using?
Have you tried logging out and then back in?
Can you share with us Appium Studio logs? Collect Support Data and share the file with us. You can upload it to a trusted file sharing service (Google Drive, Dropbox) and post the link in your reply to the post.
https://drive.google.com/drive/folders/0B9s8oTLlv269YjVpRDN5LV9Fekk?usp=sharing
check this link for logs