Bought from delhi saket oneplus store
Yes, Don't know how these guys getting the phone from Offline stores.
Now the official TWRP is available and you can use this guide to Root Oneplus 6 easily
Download OnePlus 5 OxygenOS 4.5.8
OxygenOS 4.5.8 OTA for OnePlus 5 – Coming Soon
OxygenOS 4.5.8 Full ROM for OnePlus 5 – Download Here
Guide for both the Rooted and Non-rooted Users to Flash this OxygenOS 4.5.7 on Oneplus 5.
Both Full ROM and OTA zip are available
Download OxygenOS 4.5.6 for Oneplus 5 - Direct Download Link of FULL ROM and OTA
Follow this guide, you can find the video there.
Root Oneplus 5 and Install TWRP
Follow this guide t o ROOT ONEPLUS 5
Download Oneplus 5 usb driver aka Download Oneplus 5 usb driver with full installation guide in this post. Oneplus 5 usb drive is very usefully...
From here you can download OTA and Full zip files and install the same on your phone...
Guide to install The ROM one oneplus 3
here are the detailed instructions and download link to flash the ROM on your phone...
Here are the ZIP files and instruction to update the phone.
Update it manually -
Guide to instal OxygenOS 3.2.8 ROM
Install the fuLL rom ZIP FILE http://www.technobuzz.net/oneplus-3-oxygenos-3-2-6-update/
Updated the Phone With 3.2.2 with this guide :-
Download And Install OxygenOS 3.2.2 for OnePlus 3 (OTA + Full ROM)