\(z=2.1\) falls outside the region \(|z|<1.96\), which suggests that \(|z|>1.96\) is the rejection region for a hypothesis at a 5% significance level. (We know this because \(\mathbb P(|Z|<1.96)\approx0.95\).) Because \(z\) falls in the rejection region, presumably this means you are rejecting some null hypothesis. But it's difficult to say for certain without any more information.
