@arunkm Those are probably questions better placed for an Indian LTE forum more focused on the networks. I'm in France so have no knowledge or experience of that. With that said, I've never seen my V1 not aggregate where there's signal for multiple bands and I have two bands selected. It only does one band only if there really is only one band it can receive. So if there's more than one band available, but it's only getting one, then it suggests a carrier limit. The test I'd do is to try it on all of the possible single bands and see what reception you get on each. 

@Denarius When you say you have selected two bands.How did you do that? I can't find a option to select two bands in my V2. I am sure I have 3 bands signal(B1,B3,B40) available in my area for the network I am using. I guess in V1, we can install a beta firmware and select bands manually but I want the same for V2. When I try to install V1 beta on V2, it does not allow, throws an error.

@Denarius My experience differs. I am in Austria, and it does not ALWAYS manage to establish 4G+. In my location, it is actually newer does. iPad, phone and another mobile router with the same SIM all do. The bands are B1 and B3. I can do any combinations on my phone. Also, to be honest, the speed difference is not huge. On MR600, when there is no heavy traffic, I get consistent 70+ / 19+, on the phone 80+ / 20, The jitter is lower on the phone. My signal reception quality is nearly perfect. The latest firmware and beta one do not support B1-B3 aggregation, but B3-B3 (two modes for that) should work. It does not. Honestly, I can leave with it, but I feel stupid to pay double price for something that cannot be used. The MR600 4G+ limitations SHOULD be clearly indicated in the specs and ON THE BOX—just my 2cc.

I am rather sceptical that the "development team will "fix" it, and I do not understand the reasons why tp-link cannot go with Open Source for the firmware.  

@arunkm It's in advanced>network>internet: a dropdown that says 'Band: Auto', by default. Page 14 of the manual. It's there in the stock firmware on the V2. 

@Denarius Yes thanks got it. Actually it was giving error when I search bands manually that is why I thought we need to have some other beta firmware to select bands manually. When I turn off mobile data and then try searching bands manually, I am able to select it. No need to have any custome firmware, its there by default.

@arunkm 

I have MR600 v1 which supports 4G+ on both stock and beta firmware. WIth Beta I am able to select the Bands.

I get 4g+ with with two combination of JIO  B3+B5 and B5+B40, just like I get on my phone.  I am in rural area. While in Hyderabad I never saw 4G+ either with Airtel or JIO. 

Have you checked 4G+ on phones in your area. Most of 2019+ flagship phones support 4g+?

@OwnStorm I have Pixel2, never got 4G+ in it. My area is also very interior rural area. I have MR600 V2 which has option of selecting band by default. I tried with Jio, Vi, Airtel but never got 4G+ in MR600. Not sure whether 4G+ is available in my area. Need to know how to find whether 4G+ is available in my area for any network.

@arunkm I too recently purchased the MR600 V2 by assuming the capability of Carrier Aggregation.

The band selection option allows to select multiple bands. But the router connect with only one of the band at a time. It never aggregate it.

To check the 4G+ availability on the specific location you can use the Android apps like NetMonster which gives you all the information.

So far i am unable to get 4G+ with this router. At the same time my old Samsung mobile does the carrier aggregation at the same place.

I contacted the TP-Link India support yesterday and the support person was clueless about my requirement and requested to mail to their L3 support team. Hope we will get some solution soon.

@Kathir Try to select the same bands in the router as your Samsung phone connects for aggregation. 

@arunkm I tried all the permutation and combination. No luck :(.

I tried both Airtel and Jio with different band combinations. No 4G+ sign in the router. At a given time, it connects with only one band.

Do you have managed to get 4G+??