Assuming you are asking if an infant bassinet can be placed on the floor and not if a bassinet made for adults can:
The answer is yes, an infant bassinet can be placed on the floor. There are no real safety concerns with doing so as long as the bassinet is sturdy and not wobbly. The main reason you might not want to do this is because it can make it harder to pick up your baby in the middle of the night. If the bassinet is low to the ground, you will have to stoop down more to get them out which can be difficult when you are sleep deprived. Another consideration is that if your floors are hardwood or tile, they may feel cold and uncomfortable for your baby to lie on. In that case, you would want to put a blanket or something soft down first.