@ktech786 Jazakallah for the appreciation dear. but i am not that experienced. just learn from my mistakes.
@aryaans078 first thing if you know your car's radiator is in a Bad Shape and has rust you should not be running on AC bad for the engine, bad for gaskits and seals if it heats up you will end up having the head faced a dead head gaskit and a huge bump on your Bank Account.
Rust is due to the reason that you are using water in the system rather than a proper coolant, you dont have a T-Stat and the Fan is on Direct. You should get the whole thing checked, serviced and if required change of parts.
Your AC is either tripping because your Evaporator (Inside the car) and your Condenser (outside the car) are choked this is the most probable cause. Also it can be the AC Fan Speed and the wiring heat up that can cause this.