Chapter 14 - A Preview of Calculus: The Limit, Derivative, and Integral of a Function - 14.1 Finding Limits Using Tables and Graphs - 14.1 Assess Your Understanding - Page 877: 21

no limit.

As $x$ gets closer and closer to $3$ from the left, the $y$-values get closer and closer to $3$ but as $x$ gets closer and closer to $3$ from the right, the $y$-values get closer and closer to $6$. Hence because the limits from the two sides are not equal, there is no limit.