why magnet cannot attract a magnet  like north north

Dear user

Have a look at the magnetic lines of force in the given figure.

Magnetic lines of force originate from the North Pole and end at the South Pole. Also you need to remember that these lines can never intersect each other.

When two north poles are brought close to each other, the magnetic field line emerging from the north poles also comes close to each other.  As these line cannot intersect, they try to push the magnets apart to create more space between them. For this reason, like poles of a magnet repel each other.

I hope it helps you

Best wishes!!