Wireless Mouse Disconnection During Factory Reset

I was tying to restore the iMac at my office to factory reset by pressing command and R keys. My screen came up with a picture of my mouse. I'm not sure but i think it was trying to connect. Still pressing the command R keys, the macOS utility page came up. In the process of attempting a selection, i see that mouse is not connected. The green light at the back of my mouse came on but i can't seem to identify why it is not working or connected with my iMac