Dr, I have severe itching in leg with red rashes for last two days & reduces on Avil tab. 'm on warf 6mg & HCQ 400. Is it medicine's allergy?

Probably not. but you need to talk to your doctor about this issue. Warfarin rash tends to induce huge bruises and likely more generalized than confined to the legs. However it is possible that this may be from HCQ especially if it had been introduced within the past month or so. If problem persists, you may need to see a dermatologist. If it is helped by Advil, (ibuprofen) I would look for the presence of vasculitis.