Can somebody give us the website names which are having latest and
excellent 3D animations of subatomic particles like protons, neutrons,
electrons, gluons, strings etc. so that it becomes easy to understand
how they work at subatomic levels?

There are several sites which show the scales of physical phenomena

often called 'powers of ten'

Here is a list of most of these websites:

http://www.vendian.org/envelope/dir0/scales.html


For your interest (small objects) you should go from E-10 down to E-15

You can start here, whith atoms:

http://microcosm.web.cern.ch/Microcosm/P10/english/P-10.html

Happy journey

Hedgie