Most disconnects are not caused by the server but either from the client crashing to the desktop or your Internet Service Provider losing the connection temporarily. There are far too many things that can affect your connection stability for anyone to provide a simple solution.
Are you on landline or Wi-Fi? Do you share your connection with other people? Do you use 3rd party software to boost your connection? Does your ISP throttle your connection once you surpass a monthly/weekly download limit? Do you have issues with other games or only Nostalrius? Do the disconnects happen regularly at the same time? Are you downloading or streaming stuff in the background?
Ty for the response, but client was crashing nor my ISP lost connection but I didnot encounter any disconnects till now, so if I do encounter them, will notify you