@Sunshine 

If your list (SIM card format, LTE Annnas, Software) is compete, then there really are no differences for
1. the chipset?
2. the circuit diagram?

I am asking this because if for the electronics V2 and V3 basically are the same, then you could easily and fully functionally flash a V3 with the OpenWRT firmware primarly matching V2. This would make another great option and certainly make V3 even more attractive to buy. Because V3 is a really nice LTE router. I already own 2 of them, being highly satisfied with them. And until now, I did not want to brick one of them erroneously while trying to flash OpenWRT for V2. Therefore, if you can confirm that electronically they basically are the same, then I will test-flash one of my V3 with OpenWrt for V2. And I certainly will post the result of it.

  @daihedz 

Hi, are you sure that there is an OpenWRT version for the Archer MR600? I understood that the MR600 listed on OpenWRT is a completely different make (not TP-Link). Also, I understood that one of the difficulties for OpenWRT (and DD-WRT) is the X12 modem used by TP-Link. But maybe I am wrong.

Thus it would be great if TP-Link inputs to OpenWRT and/or DD-WRT to make this work.

If you have installed OpenWRT/DD-WRT on MR600 v3 succesfully I would be delighted to hear from you! 

Best

  @Parag18 

There indeed seems to be binaries for the genuine TP-Link MR600:

https://firmware-selector.openwrt.org/?version=23.05.2&target=ramips%2Fmt7621&id=tplink_mr600-v2-eu

However I realized that there is no "certified" OpenWRT HowTo. Instead, I only found a technically way too exorbitant Youtube HowTo:

https://www.youtube.com/watch?v=sjkU99-2onA

I certainly will not follow this "guide", because also the feedback posts are not so inviting to do so. Therefore I also hope and wait for OpenWRT to provide not only the binaries, but also some more foolproof advices for theirs installation.

Meanwhile, I pragmatically decided to revert to use the MR600's as LTE modems only and daysychain them with OpenWRT-flashed AVM Fritzbox 4020 or 4040 to provide the nifty OpenWRT bells and whistles. Both these models have a dedicated RJ45 WAN connector and 4 LAN connectors for easy connection in such a setup. I can tell from experience that this setup is functional, because I run two 4040 and one 4020 in exactly this configuration, all three AVM's flashed with OpenWRT.

  @Sunshine Tomorrow i purchase Tp link Mr600 v3 Router

When i choose band selection manually. it always show there band only. but for your kind information here is Band 8 working. but this router is not showing band while searching. i have tried so many times but not showing band 8 to select. (With Airtel and jio).

I have also Tp Link MR6400 router in which i have beta version for band selection. In  that router Band 8, band 3 band 1 AND band 40 and 41 all are showing. But why not showing in this Mr600 please help me to sort out this issue. as i have to live stream and for that Band 8 is best working in my region.

I am attaching the photographs of the Router and screen shots of the same. Please feel free to contact any time,

Manpreet Singh. I have seen many videos in all videos Band 8 is showing but in my router why it is not showing? i think there is problem in your product please get it done or please return your product.