If it's a porcelain sink this post might help
Hi Carolyn, here's a handy guide that will help you get rid of those rust stains - https://homeguides.sfgate.com › rust-out-sink-50684
CLR cleaner, or Wink
Porcelain or stainless steel?
Hello. I have had good results using CLR on rust and calcium stains.
Barkeeper's friend and magic eraser
Here's a post that might help - https://www.plumbingprofessors.com/water-issues/iron-stains-on-sink/#targetText=Wet%20an%20old%20toothbrush%20with,effective%20at%20removing%20rust%20stains.