Hi Finally i solved the big problem after all i spend some and wondering what if i gone mad due to high tem.
Now i gone one step ahead and opened the hsf and found the thermal paste is outside the chip and nothing was in the chip.
I had thermal paste left ahead from my cpu hsf kit. So applied the paste after whipping completely and then carefully remounted HSF to the board and then powered on my system.
I ran the test both are at the same temp on furmark burn in test reach 80 degree.
I can now freely use the card without any issue.
Thanks guys for your help.