Is Magnetic Field Attract Toward Hard Chrom Coating Aluminium?

What exactly do you mean by 'not affected by a magnetic field'? An aluminum frame is a good electrical conductor, and as such significant forces may result when rapidly entering, exiting or moving in relation to magnetic lines of flux.

It might be helpful in determining appropriate coatings, to know why you want to coat the aluminum.

One generally anodizes aluminium.

One generally does not electroplate aluminium.

If you intend to introduce a circle of aluminium into a magnetic field - expect it to be ejected -quite energetically.

It might be an idea to explain what you intend and why you ask - before making such insecure assumptions on how what works.