Thanks for your quick response @_Leo_
I have one more query, I am able to get the ADC readings properly, But after removing the sensor also the ADC showing random garbage values, Is there any function like stopping the ADC temporarily.
I have seen in the Reference Manual that in ADC_HCn, the if the first 5 bits all are 1 it will stop hardware triggering. How to achive that thing, I tried but it didn't work.