Is there a way to check if text is in cyrillics or latin using C#?

Use a Regex and check for \p{IsCyrillic}, for example:

if (Regex.IsMatch(stringToCheck, @"\p{IsCyrillic}"))
{
    // there is at least one cyrillic character in the string
}

This would be true for the string “abcабв” because it contains at least one cyrillic character. If you want it to be false if there are non cyrillic characters in the string, use:

if (!Regex.IsMatch(stringToCheck, @"\P{IsCyrillic}"))
{
    // there are only cyrillic characters in the string
}

This would be false for the string “abcабв”, but true for “абв”.

To check what the IsCyrillic named block or other named blocks contain, have a look at this http://msdn.microsoft.com/en-us/library/20bw873z.aspx#SupportedNamedBlocks