Finally the missing of my car on idling and at low speed ended with the replacement of ignition coils. According to mechanic it happend because the car got overheated and so the coils got stretched. I could also see a space on a joint of each coil that was created because of overheating.
Instead of new ones which were costing me around 10000 each, I managed to get two kabuli coils @ Rs 5000 each.
The second job was replacement of gear oil and ATF Filter which ended up the constant jerks which I used to feel while increasing the speed from 30 to 40 km/h.
Prices are listed as :
Gear oil cost = Rs 4370
ATF filter cost = Rs 1950
Labour = Rs 500
Alhamdolillah now the ride is as smooth as new.
I hope this post will be helpful for many armatures like me .