this tartan in Northern Ireland?

[John_Carrick]

No one will mind. They may ask out of politeness or interest what tartan you are wearing, but people do not attach great importance to it. If you wear a kilt, in all likelihood people will assume a unionist identity, but people in all 32 counties are pleased to see kilts and tartan and nearly every Irish town has a pipe band or two. Kilts not contentious generally and particular tartans will not raise any ones hackles.
My advice is to listen with interest to people's perspectives if they offer them and don't lecture them about their own history.
I wear a kilt all the time and have never had a problem in any area.

I would not agree with Figheadair's last sentence and would amend it to say that once people realise you are not from the six counties they will assume you know little about the place. I would be appalled that people might think that there are areas of anti British sentiment here. This is simply not true of any part of Ireland. There might be a few with opinions about what governments and state institutions might have done in the (increasingly distant) past, but that is different.

It is a nice friendly place to live, but the weather is something else!