You have quite a large bulge of the disc, though I wouldn't call it "massive". But big enough to give you lots of pain.
One important thing: if it comes to surgery, there is doubt in my mind about the level. The radiologist says the extrusion is at L5-S1 - but there is clearly a (rudimentary?) disc below L5. Either he has the level wrong, or you have a "lumbarisation" - a sixth lumbar vertebra.
That could make it difficult for the surgeon, and he could go in at the wrong level.
Do you only get pain when walking? If you bend slowly forwards do you get pain in the leg?
Do the "slump test" at Chiropractic-Help (use the Search this site function) and leg me know what happens.
Can you stand on one leg, first on your toes (raise your heel) and then on your heel (raise the big toe)?
This is the sort of condition that can be reduced with careful manipulation, but whether you can find a chiropractor in Bargarh is another matter.
Sit much less, do the back exercises at C-H, don't sneeze, don't bend and given time it may heal of itself.
I hope this has contributed. I would suggest you print this out, and give it to your doctor. The surgeon must obviously operate on the correct level. A good surgeon would of course pick this up immediately.
Dr. Barrie Lewis