I'm not familiar with Tajik or Russian keyboard layouts but this looks like something that probably can be configured and therefore likely is a support question.
Did you try to ask your question on any of the support channels like IRC or ubuntuforums.org ?
Can you provide your current xkb model, layout, variant and options settings by running the following command on a terminal:
$ xprop -root | grep XKB
I'm not familiar with Tajik or Russian keyboard layouts but this looks like something that probably can be configured and therefore likely is a support question.
Did you try to ask your question on any of the support channels like IRC or ubuntuforums.org ?
Can you provide your current xkb model, layout, variant and options settings by running the following command on a terminal:
$ xprop -root | grep XKB