after some research i found out that it is neither the MAP nor the TPS but it is the fault of ISCV
ISCV=Idle speed control Valve
The ISCV can be removed easily by opening the 4 Throttle body nuts at the Intake side . and do remove the HOT water lines going in the ISCV. the function of this sensor is to increase the RPM of car when cold and as the required temp is reached it signa;ls the ECU to normal RPM.
The problem with ISCV of Baleno is that it has ECU trigger and that is to increase the RPM as the AC is turned on. Toyotas usually have a separate idle controller / enhancer to increase rpm on AC usage and it doesnt go bad easlily.
The baleno,s ISCV gets very dirty (as time passes) and starts giving bad signal to ECU and the fact is it can even happen on petrol too . CNG aint the only factor for that and the "Chek Engine " light comes up.
Replacing the ISCV sensor is recommended but cleaniing it by WD40 or petrol also enhances the ISCV,s life(remove before cleaning).
or try this !
1.remove the air intake plastic pipe
2.start ur car on petrol ( dont accelerate)
3.u will see a small channel in the bottom of the throttle body, spray some WD40 in it and accelerate the engine around 3500 RPM for some time
4.repeat the procedure (it will clean the channels and the jammed solenoid of ISCV usually gets free)
5.If above doesnt work, replace the ISCV , or clean by removing it