If you are looking for an app to control your TV rather than hardware firmware, you can download various directly from official stores:
: A Sony Remote Control app is available through the Microsoft Store.
If you specifically need the .rar file to flash a TV board (like a TP.VST59.P83 or similar universal board): Remote For Sony TV -WiFi/IR – Apps on Google Play
Searching for a "SONY REMOTE 1366 768 rar" file usually refers to downloading for a universal LCD/LED TV mainboard configured for a Sony remote and a screen resolution of