Changing the tick time in FreeRTOS
See the configTICK_RATE_HZ configuration option.
Also note it is better to specify times in milliseconds, rather than ticks, so you can change the tick frequency without effecting the timing (other than the resolution of the time).

The pdMS_TO_TICKS() macro can be used for that purpose, for example to create a delay of 100ms.

const TickType_t xBlockTime = pdMS_TO_TICKS( 100 );
vTaskDelay( xBlockTime );