I am trying to apply digital signature to the documents using the Acrobat SDK. Is it ok to install the Adobe acrobat pro on a server machine and use it for applying digital signature for the documents?
Is Adobe Acrobat pro license allowed to use as mentioned above?
What license would fit for above requirement so that we can procure and use?
No, this is absolutely forbidden by the license, which is for a single human logged in. No server license is available. Acrobat is not technically suitable either (it always runs interactively and pops up prompts at times). Maybe look into Adobe PDF Library from DataLogics (Adobe's library, maintained and distributed by DataLogics). Licensing is by negotiation.