*** UPDATE ***
I took the car to my mechanic and he said first get it checked from a key & lock expert, which i did and that fellow said no problem with the lock and recommended that I go to an electrician coz he said normally such problems are electronic/electrical related.
I took the car to a mechanic at Waris Road (recommended by a cousin who imports JDM Vehicles) when the console covering the gear area was removed the cable which removes the lock from the ignition key when gear is in Park was found to be disconnected. Its mechanical system where the cable is pulled when Car is in Park, hence allowing the key to turn back completely and be removed from the ignition. There was a small plastic clip which held the cable in place it was found to be broken due to plastic having become brittle, the electrician tried to search for a replacement but proper size clip was not found eventually he placed the cable back in place and fixed it to the broken clip with Epoxy. There was no problem found with the gear shifter, now the problem is totally solved.