If your remote isn’t working properly, please see Sony’s support article: How to troubleshoot a remote control that quits working or does not work properly.
If you are trying to use the Touchpad remote for the first time and it is not working, it could be because the remote has not been paired to the TV. For instructions on how to pair your Touchpad remote please see Sony’s Support article: How do I pair my Touchpad remote to Sony's Android TV?