Question

How to solve complex resistor circuit questions...I mean the proper approach to solve such questions.

Answer 1

In a complex resistor circuits remove the resistors where only one terminal is connected and another is open because that resistor doesnt contribute anything

Second lookout for wheatstone bridge combinations of resistors so through the resistor through the current doesnt flow can be removed.

Try to reduce parallel and series connected circuits so the circuits becomes a little bit easier.
While doing so be aware of the parallel and series combinations. There is a chance for to take the combinations by mistake.

By doing so its easy to solve...