Have protruding nipples. Any suggestions to stop the looks?

Bra inserts. There are inserts that can be placed in your bra to hide prominent nipples. Some padded bras work nicely as well. There are a few bras that have these inserts built in.
Yes. Protruding nipples can be helped by a small operation to reduce the projection of them. Large nipples are a more difficult problem. I'm not aware of operations to reduce them but a wedge excision is most likely the answer. See a plastic surgeon for your best options.