The thing is I have 10 TP-Link WIFI routers in my network mostly TL-WR740 and TL-WR840, the thing is all routers works fine, but just some of them I can access the GUI with their IP address.

I Have identified some routers but some of them I can't even know where they are installed, I only have the IP range where all routers are, as I said I can access some of them and could identify the department which belong, but some others can't connect to the GUI.

I been having huge Internet usage in router 192.168.0.146 but I can't even know which router is.

DHCP is disbled in all routers and the ER-6120 is the only one who route with DHCP from 192.168.0.150 and this difficult the search.

There is a software to manage all my wifi routers? or any way to log in into their GUI from my PC? 

IP's range for routers:

192.168.0.140 to 192.168.0.150

192.168.0.143 can access to GUI is from DMV depertment (TL-WR740)

192.168.0.144 can access to GUI is from TREASURY department (TL-WR840)

192.168.0.147 can access to GUI is from PUBLICS WORKS depertment (TLWR740)

The rest of the routers can't access to GUI via IP adress 

To do it physically I have to go every department and disconncet all cables and conncet a laptop to the router and try to get in from there, but many people is using the routers during the day. 

The building is huge 43000 sqft in 4 floors I would love to manage all routers from my office.