No, slot machines are not rigged. They use Random Number Generator (RNG) technology to ensure each spin is entirely random and independent of previous outcomes. The casino's advantage comes from the built-in "house edge," which is a mathematical advantage that guarantees a profit over the long run.
Therefore, there is no way to predict when a slot machine is going to hit, and any strategy or system claiming to do so is likely to be based on superstition rather than fact.