Well that is also patently false. Perhaps you should expand your sources of information, because you seem to be woefully misinformed on a number of topics relating to this case.
Those "Russians" that "want their day in court" are refusing to step foot in America, let alone court, because they know that will likely mean a long stint in prison for their many crimes committed against the United States. But it is revealing that you seem more concerned with the welfare of these Russian Intelligence operatives than you do with the fact they attacked the United States of America. Why do you think that is? :thinking
Mueller did not say he wasn't ready to deal with it. Mueller's team has been handing the legal team of these Russian Intelligence operatives asses to them in court for a while now. Most recently having the judge openly rebuke and admonish the legal team for these Russians who attacked the United States, for their behavior in court filings.
https://www.washingtonpost.com/politics/courts_law/judge-rips-attorney-as-unprofessional-in-russia-probe-case/2019/01/07/1cba1ada-12a5-11e9-ab79-30cd4f7926f2_story.html?utm_term=.f23f4c8b9a01
As a result of Mueller and Team handing the Russian attorney's their asses, the counsel for the Russians who attacked the United States has suggested that they may have to withdraw their representation of these Russians who attacked the United States.
Don't you think it would make sense to become better informed on these very serious matters?