What is this bad archive mirror error

    I am installing via usb dual boot, installing graphical and getting this error. I am from India and am not able to proceed further, Could anyone please help, also attached the image  

Try selecting a mirror in your country or a different mirror.

JT

Which Debain version are you installing?

I have same problem, i tryed to install  2.8.2  and 2.8.0 freshlly downloaded from websites. I used Rufus to burn it to USB flash disk (no problem), when i insert it to computer (Dell 7010) and try live version everything work great, latency test and even internet. But when i try to install it and have connected internet cable to computer, installer freeze for 10 minutes (same behavior when i tryed to install on my main computer). When i disconect internet cable it show that no network was found and proceed to next step. 

It seems that everything is installed but then i get same error as shown in picture above. When i want to proceed without this step it stop on next step "GRUB installation failed"

I noticed that everywhere is "-amd64" (on live version etc.) but i have intel CPU, did i done something wrong ??

Try installing the official ISO without internet, worked every time before.
And amd64 is OK for intel, well it is the only one for 64 bit intel but the AMD name stuck to it as AMD was the first to officialy sell 64 bit cpu.

By "official" you mean linuxcnc.org/downloads/ ?
I tryed that "LinuxCNC 2.8.2 Debian 10 Buster PREEMPT-RT ISO", but with no luck.
I tryed to install Ubuntu 20.04 LTS with no problem, same proces, download on windwos computer, burn to USB with Rufus boot and install, no problem at all. I only think that i saw some error lines when booting but they disapear so quickly that i didn't even had time to recognise what is going on.

So it's there some easy way how to instal LinuxCNC on already installed Linux (Ubuntu, but i can try to install other one) ??