Problem resolved by doing
"Through" of brake discs. I dont know whether lathe machine guy was saying "Through" or he meant "Tooling".
Now brakes are good. Also I ensured that brake discs were mounted on hub using Hydraulic Press instead of hammering.
As far I know, by hammering discs/wheel bearings on hub, there are two damages:
1. Dis-balancing of brake discs/rotors
2. Damage to bearings
So whenever mechanic tells you that he is going to hammer the brake rotors or wheel bearings, kindly stop him. And goto lathe shop having hydraulic press and ask them to mount wheel bearings and brake discs/rotors by means of hydraulic press. You will need to take whole Hub to lathe shop for this purpose.
Usually lathe shops have hydraulic press. But in case you dont know, there is one opposite khan motors on main korangi road (DHA Karachi). You can ask khan motors for location of lathe shop of "Basheer".