Hello Skill,
Thanks for your continued help
I just visited one more good mechanic.. Haven't shown him the car yet.. Told him about my whole problem.. He too suggested that this could be the problem of VALVE SEALS due to bad oil (ZIPEX)..
I will visit him tomorrow to get my car checked.. He said that he will check 2 or 3 things first (VALVE SEALS, TAPPETS and GASKET), before opening or entering in to the engine.. He also said that; if it isn't the problem of above 2 or 3 things, there is no need to get the RINGS done.. Simply get your engine replaced in 30 to 35k (give mine one along) and get sakoon mahol for next 5 to 6 years 
I hope that I will get safe from getting the engine opened..! By the way; the current engine mileage is 1.80k...
What is your opinion? Or please for one last time; tell me the exact things I may get checked or replaced before getting in to RINGS...!
(P.s: I got my radiator cleaned up on my last trip, as the car was becoming so hot.. And I found that the radiator was almost full of dirt and the water wasn't getting circulated properly. But after radiator clean up the heat-up problem got almost solved)..
Thank you very much and may ALLAH TALLAH bless you and all other members, who are helping people like me 
Please let me know; if you require any further information regarding my car, that could be helpful..