RFID Counter

Hi!

Sorry if this is a reopened topic, if another is opened please redirect me, couldn’t find it.

So, I am making a system that integrate a UHF RFID reader, 8 tags and a raspberry pi with Bluetooth that communicate with a robot.

The reader is on a trolley with shelves, after the reader count 8 tags it must send a signal to raspberry and raspberry call the robot.

My question is :

Is this achievable? To count the number of tags? I consider if i can count them and send a signal to raspberry, the rest is workable.