Hi Ragavan,
I bought Nexus 5 d820 model from Google playstore US factory unlocked and was trying to follow your method. I could unlock the boot loader and boot in diag mode, however when I'm flashing reliance PRL it's not sticking at all. After reboot nothing happens and I don't get reliance tower. Could you help? I'm using the above method on out of the box new piece phone. The os is Kitkat 4.4.0.