How to retrieve specific text (like comments) from pdf or docx?

You can try this plugin available on App market.

Hi, specially for PDF kind of documents you can use the IDP feature to read the complete PDF document. 

Hi kajalp8940,

You can extract data from doc in many ways, you can try with IDP or Plug-in or you can create a Doc extraction process using below link.

Doc Extraction

Thanks for reply but I have to retrieve only comments and page no from pdf.