Phone not booting after OEM lock Device: Yu Yunique

I flashed stock fastboot ROM (YU OS) and it booted. After that, I did fastboot oem lock and the phone not booting. Fastboot doesn't allowing me to flash another ROM too.

I googled about this and it says I need to enabled USB debugging from developer tools. But since the phone is not booting, I am not able to do this.

Can anyone help please?
The mistake was to leave "USB debugging" and "Allow OEM unlock" options unchecked. Just make sure both are ticked when phone is on or you have to visit service center. Sadly, no other solution is there.