UNIX for Advanced & Expert Users

Hi,

I have login as root user create a folder call engin at /usr/local , then change it owner and group to another user egr.
Then login as egr and create a folder call nt at user home directory.

This 2 folder are having same owner and group. When I login as egr I try to copy file from folder nt to folder engin, it prompt me error permission denial.

Why it can happen even though I am the folder owner

I just have this doubt,

in whose home directory have u created the folder 'nt'
in root's home or in user egr's.

if it is under root's home, the two folders cannot have same owner and group.