Human detection Label ID

Can I know is there any possibility to keep the label ID of a specific person same all the time even he gets out of the frame and comes in again.

Is there any way of detecting a specific person and track only him in the group of people.

If you set the ObjectDetectionParameters::enable_tracking_ to true, a same object will keep the same ID as long as it is seen by the camera (however it can be occluded for a few frames and keep the same ID).
If the object goes out the frame and comes again after a certain time, then it will have another ID.

That being said, a future release will have the possibility to keep the same ID by re-identifying the object even if it goes out and in again. If everything goes as expected, it should be in 3.5 in a few weeks.