Dear @Djaymx & @daniyalcars72, thank you for your valuable feedbacks.
I believe I ve found out the issue.
As I mentioned earlier that a tuk tuk sound was coming from the suspension after the brake pads installation but I was actually wrong. The tuk tuk sound was not coming from the suspension but instead from some AC part. Because I could hear it on idle with ac turned on and it vanished when I turned off the AC. Also the loss of power / missing is felt when AC is turned on. Without AC the car accelerates smoothly.
The car was working fine even with AC turned on but the cooling was not upto the mark. So I took it to the workshop and they told me that the gas was not full. So they filled the ac gas and this issue of loss of power/missing and tuk tuk arose after I got the AC gas filled. The AC now is somehow working fine while the car is in motion but at idle it doesnot work.
What could be the reason?