Jasper Reports PDF doesn't export cyrillic values

Jasper report uses iText and always when a char is not rendered in pdf this should be the checklist:

1. Is my actual .tff supported (OpenType) and can the font actually render the character. Not all fonts render all characters in UTF-8, see How can I test if my font is rendered correctly in pdf?
2. Do I pass correct encoding to iText. In doubts (or in general) use the encoding Identity-H this is recommend for newer PDF standards and gives you the ability to mix different encoding.
3. Is my font embedded so that if I share the pdf also computers not having this font can display the content?

How can I ensure this is JasperReport?

The deprecated method was to set attributes on the textElement

<textElement>
  <font pdfFontName="Helvetica" pdfEncoding="Identity-H" isPdfEmbedded="true"/>
  <paragraph lineSpacing="Single"/>
</textElement>

The current non deprecated method v 3-6, is to add Font Extensions and this is easily achieved by using tools like iReport or JasperSoft Studio that can generate a .jar of your font extension so that you can include it in your classpath directly.

How to generate font extension .jar using iReport or JasperSoft Studio.

EDIT: The problem of OP was 1 on checklist (.ttf font could not render), but surely he should consider both 2 and 3 using non deprecated method.