Blood of other on hand. for hiv u have to have big cut or small n bloof of other in one drop is enough or require large amount?

Depends on amount: The risk is proportional to the quantity of blood. If your skin is intact and you get HIV blood on you is is a pretty small risk. If stuck with a pin it is still small risk. If dtuck with a Insulin needle from HIV positive it is higher risk. As the size of the needle increases you also increase the risk because of the increased volume of blood.