I have the following scenario, there is a RFID tag attached to a certain object which also have a light sensor on it (this is just for illustrative purposes, it could be another type of sensor), I want to know whether it is possible to tell the RFID tag when the light sensor is on/off or put another way, can the light sensor just somehow connect directly to the RFID and inform its on/off status so that whenever I read the tag with the RFID reader I could know that the light sensor is on/off, thanks in advance
Yes, there are RFID systems that are designed for this purpose. They do not "override" the RFID tag per se, but the tag is able to report back the sensor value as part of ts response when queried by the reader. They are commonly called things like "RFID sensor tags" or sometimes "energy harvesting sensors" for systems where the sensors are powered solely by the RF energy received from the reader. These are commonly used for environmental sensors, like temperature and humidity, but conceivably any sort of sensor could be used. Of course if you want a batteryless RFID sensor, the sensor itself must be able to operate on the very limited energy available from the RD reader.
There are specialized RFID ICs that can be used to create custom devices, several of the major IC vendors have options in this market.