My uncle received a notice that a written objection has to be filed because he filed bk 6 years ago. what is needed for this objection

I'm sorry, but your question is far too vague to answer. Who sent your Uncle this notice?  What is it your uncle is supposed to object to?  Who is seeking the objection?  What Chapter of bankruptcy did he file?  Did he receive a discharge? We need far more facts to even begin to understand what you're trying to ask.