btw, does Note4 N910u support T-Moblie 4g internet ?
Your best bet is to use a couple of tools to verify:
BYOD & Sim Cards | Get a Sim Card For Your Unlocked Phone | T-Mobile
The simple phone search says your phone will work,however,I'd use the advanced search,in which you enter the IMEI.
However,I suspect all you will get is a generic response that the phone will work,but,not specifying if 4G/LTE is capable w/this model.
I'd suggest posting/looking here:
http://androidforums.com/t-mobile/706991-how-tell-if-phone-will-work-t-mobile.html
From the information given,& a GOOGLE search of your model number,this phone will not work on the LTE variety of 4G.
2G Network GSM 850 / 900 / 1800 / 1900
3G Network HSDPA 850/ 900/ 1900/ 2100
4G Network LTE 800 / 850 / 900 / 1800 / 2100 / 2600
I suggest you read the OP from the link carefully,as your phone does support 3G,it's still questionable if it supports what is commonly referred to as FAUX-G,a faster than 3G technology,but,depending upon various factors,may be just as fast as 4G speeds,or,just as possible,somewhere between 3G & 4G speeds.
There are a lot of knowledgeable members who are active in the T-Mobile Forum & I recommend that you post in that forum for more detailed/accurate information regarding T-Mobile compatibility.