XAMPP for windows 64-bit machine

Yes, it's fine.

A 32 bit build will run fine on 64 bit Windows.

Php and Apache don't have official supported 64 bit Windows builds, only MySql out of the three does, hence no 64 bit bundle.

it possible to run 32 bit XAMPP on 64bit machine. it is all fine, so far there is no 64 bit XAMPP application. personally I use 32 bit XAMPP server on 64bit windows 10 machine. it works fine for me.