I use the genuine Nissan coolant. Not because of loyalty but because I was at the parts counter when I remembered that I had forgotten to buy some at Repco earlier that morning.

It doesn't really matter what one you get as long as you remember two important things.

1. Get a well known & reputable brand & read the label before buying.

2. NEVER, never-ever mix two different coolants as some of these will react in a very negative way with some others, & you usually don't know about any negative reaction untill it's too late & the damage is done. [coagulation, blocking the radiator]

If you do not know what's in the engine now & you want to top up, then dump the lot, flush it once or twice, then start from square one. Remember to flush the heater too.

I know that you are near a major parts outlet, so geting something suitable should not be hard, but get enough to have a little left over for top ups later on.
Keep the empty container somewhere visible to remind you next year you what you had used.

I learned all this from the literature at my local radiator specialist while waiting for him to finish a job for me one day.