Finally I bought the Autolite XS4163 Xtreme performance Spark Plug from
Ubaid ur Rehman Autos, Al shamas Market, Badami Bagh
I got it in 800rps finally.( instead of 900 )
Funny thing I want to share. My last plug was too much tight that I could not open it with stock equipment in tool box, so I went to near by mechanic..
Asked him to plz open the plug as I want to change it, he opened the old and when I took the new one out of my pocket, he saw it and said "Yeh to Desi hai"
Anyway the first Difference I felt is self start time, previously it used to take some time to start. But now with new plug it starts just after touching the Self start button.
I Will go to office in the evening, approx 18Km, then I will try to feel the performance difference..
Thanks to Vicky Bhai and Umer085 for their continuous help.