How do I answer “should I connect with current affairs” in the UPSC mains exam answer writing?

Well, I think the suggestion which I would like to give you is that you should be answering and not writing. You should not go with the preconceived notion that I essentially have to write current affairs. 

So, you should answer instead of writing. Meeting the expectations is necessary and can be in the written code of every good answer. This is the way through which you meet the expectation of who you are going to be in the future. What kind of person would you be? This should be incorporated in part of your answers. Also, meet the expectations of the evaluator, the person who is seeing you from a particular perspective. So, these two things, you should be keeping in mind in written code too. 

And if I talk about current affairs. It is important, especially for those underlying current that is present in most of the issues about which the questions are asked, so you should be having it. But then you should not be kind of insistent on giving the current affairs information even if it is not asked. 

But it could be a starting point to break your answers into some startling facts about the current issue that you can give, but then it must not be the core of the questions that doesn't demand. The bottom line is that you should answer and you should not write. And you should not go with the preconceived notion that I must give information about the current affair because the question has been asked. 

My best wishes!