The font 9 on the first page of your PDF contains a ToUnicode map. These glyphs are referenced inbetween the brackets using the custom encoding of that font. The second line causes glyphs to be printed. The first line selects the font named 9 at a size of 239 (an operation at the beginning of the page scales everything down).
The top line of the first page is generated by the following operations in the page content stream: /9 239 Tf If that is not possible, you should go for OCR. You should ask the source of your document for a document version in which the font informations are not misleading. the glyphs 'निर्वाचक' in the head line represent the text 'ननरररचक'. Your document itself provides the information that e.g. This issue is similar to the one discussed in this answer, and the appearance of the sample document there does also remind of the document here: In a nutshell
