Thanks for the correction!
The carpet is all done. Clean with no odor of gear oil. The namda is in a much better state with only its edges smelling like gear oil, rest its almost clean and odorless.
I can get new insulation sheet (namda) and carpet but without the clean floor, they'll be ruined as well. :\
Point noted!
But will using detergent remove the gear oil in the bitumen layer?
Should I try hot water along with detergent if it won't damage the bitumen layer?
Ookay!
So what if I scrape off the bitumen layer?
I have heard that it can be re-done, however I really DON'T want to scrape it off as my floors and in a perfect condition, so any other option, by which I can make the situation better, If not completely perfect?
Hmmm...
In my case the area is quite large.
I think I did the stupid thing of using the Kerosine Oil which thinned the oil and made it to seep through the bitumen layer, thus evenly spreading it in every nook and corner.
Anyways I'll keep your suggestion in mind while working on it.
I have the pieces of insulation placed in my room, which have been cleaned but still my room is smelling like..... 
The area affected is quite large.
The first thing I'm trying to do is to throw out as much oil as possible, then the odor treatment will come into the equation. I won't be reluctant to try anything to remove this mess from my car.