sonia wrote:

I kept one of my plants in the hardwood floor area and forgot to place
the plate at the bottom. After 2 weeks I realised my floor was soaked
with water and there were black stains on the floor?
Is there any remedy for it that I can do myself instead of hiring
contractors? I am very inexperienced in handy work, so please give me
thorough instructions to follow through. Your help will be highly
appreciated.

Try rust remover on a small spot. Doubtful anything but sanding will
take it out.