Read the picture as a plumbing problem. Both ureters are blocked by stones, no urine is getting out, and the kidneys are backing up (hydronephrosis) while the blood numbers (creatinine $16$ mg/dl) climb. On top of that there are pus cells, meaning infected urine is trapped upstream of the blockage. The single most dangerous element here is infected urine under pressure, which can rapidly turn into urosepsis.
When urine is obstructed and infected, the textbook rule is to drain first and treat the stone later. Draining can be done from below with a retrograde double 'J' ureteric stent or from above with a percutaneous nephrostomy. Either way, urine flow is re-established, the pressure on the kidney falls, the infected material escapes, and renal function starts to recover. Among the options offered, the 'J' stent is the drainage choice.
The tempting wrong answer is haemodialysis, because the urea and creatinine are alarming. But dialysis cleans the blood without unblocking the ureters, so the kidneys stay throttled and the infection stays trapped. It is a supportive add-on, not the fix. Lithotripsy and ureteroscopic extraction are stone-clearing operations; doing them on a septic, obstructed, uraemic patient is hazardous and is deferred until the patient is stable and drained.
So the immediate move is to decompress the system.
\[\boxed{\text{'J' stent drainage}}\]