Some countries like India only includes FreeDOS and not Windows 10 (or other versions) to keep the price low. That means when you boot the laptop you will see the C:\> (called C prompt) staring back at you.
As mentioned above, you will need to install Windows in order to actually use the laptop. Be aware that 7th and 8th generation Intel CPUs will only allow Windows 10 to install and operate properly. Microsoft made a deal with Intel (and AMD) to only allow Windows 10 (and most likely future Windows versions) to be installed on current generation CPUs.
There are places in the world (like India) where stores sells laptops with only DOS installed to keep the sale price low.
It is up to you to install an operating system. You can either install some version of Linux like Linux Mint which is free (link below), or Windows 10. Intel 7th and & 8th generation CPUs and AMD Ryzen APUs will only allow Windows 10 to be installed. Linux will not run Windows 10 programs.
Otherwise, return the laptop for a refund and buy one with Windows 10 installed.