magnate = a person of power or influence (often in a specified area)

1) M A Yusuf Ali is a business Magnate from Kerala who owns the Lulu group of companies.
2) She was a magnate in the newspaper industry.
3) Real estate magnate, Media magnate, political magnate, property magnate.

magnet = something that attracts (iron)

1) Kids took out a magnet from the damaged motor.
2) I love Fridge magnets.
3) Earth behaves like a big magnet
4) Munnar is a magnet for tourists to Kerala

A Magnate might have a magnetic personality. But the two words are different.