I have a slight single leg joint pain, it has passed over 6 months, it little bit more increase when i stand and sit down. i don't know what is it? what should i do to cure it and what would be the treatment? any home treatment is available?

I assume you're experiencing knee discomfort. Any old injury? If there's no swelling, I recommend a trial of an anti-inflammatory medication like ibuprofen or naproxen, taken with food according to instructions for 7-10 days. The issue is possible osteoarthritis, cartilage damage or tendinitis. If not improved, consult an orthopedic surgeon for evaluation, appropriate testing & treatment options.