I am able to make any pdf as reader extended using readerextension activity on workbench and using https://host:port/readerextension.
Can you anyone let me know is there any other way to make a pdf as reader extended other than above two methods.
Also let me know if i can make a pdf as reader extended while designing it in adobe designer.
You can do using the Adobe Acrobat software.
Open the form in Acrobat and choose the Advanced tab and Extend Features in Adobe Reader.
Check the image below.
No, there is no way to do it within designer. It was considered as a feature once, but became too complicated and large for the amount that it would be used.
So either use Acrobat for a simple set of rights, or use the LiveCycle server for a more customized rights set and large universe of available rights, such as barcoded forms, database and webservice connectivity, and others.