Update: (Problem Solved)
After waiting a Month to see the problem still presists or not. Finally the car is running smooth again Alhamduliillah. The Problem was with TPS Grip (Throttle Position Sensor) which was causing car to drop RPM (Rpm Needle Up & Down) while driving. The Sensor is Located behind the Throttle body just where the Air Cleaner Pipe starts (Black Sensor). The Wiring Harness in Baleno is extremely tight the Grip Joints get stretched and by time become weak. After testing it for a Month the Car is Driving Smoothly. Hope it helps more people.
Thanks to All who replied and Helped me with my Problem. JazakAllah
