Whisch disinfectant in India is used on cottons used for blood test , is it alcohol? I want to ask this because after taking out the blood they are kept directly on the wound and if some infected blood (may be HIV) is already present there than there is a chance of transmission

Yes, usually, rubbing alcohol is used to clean the area where blood is drawn. But there shouldn't be any chance of disease transmission unless the same piece of cotton was used for more than one person.