How can i reduce pain in leg, calf and foot due to osteoarthritis in l2, l3, l4 and l5 vertebrae ?

Radiculopathy: It depends on how severe is the arthritis. In earlier stages physical therapy can help. Sometimes epidural steroid injections may give short term benefit.

Radiculopathy!: You are probably describing an s1nerve root compression, although a L5 is possible by your imprecise description. Pain is a paradoxical "good" sign, since pressure on the nerve is more minimal. Gravity traction may help, as might a steroid dose pack. But if neither work, your next date will be a spine surgeon. I always get an EMG before imaging the spine.