Finally the issue is sorted out !!
Car is running fine now, drove almost 50kms I dint face any issues like jerking or idling.
So I guess it was because of the clogged injectors. I replaced the injector o-rings as one of them cut while putting it back. O-ring set costs 100rs a set (This is not available with MGP). Replaced the throttle body gasket, IAC gasket.
Thank you ss80, jarpicke, joeking, juandiazmora and all for the sugesstions.
Things to be changed soon - fuel connecting rubber pipes, distributor cap. Today my car completes 10 years !! It was bought on 27 June 2003..
Very happy with it so far, I wish to keep it as long as possible.
Next : Mega DIY coming soon !