Hello dear @mili2088 :)
It is good to hear your brothers are healthy, strong and privileged enough to have the chance to look for opportunities else where. Some people don't even have that in life! Of course, you are upset because they aren't going to be close to you, that is so normal, isn't it :) but then again, that is because of attachment.
I am sure you are going to see them as many times per day it is possible. Isn't that the beauty of social media? I live miles and miles away from my brother and nephew. We talk and chat nearly every day. Things are not like they were 15 or 20 years ago, when phone calls were so expensive, we relied on letters. This are all privileges that we have and should never take for granted.
Try to map your way towards feeling good about the opportunities you family have and stay strong for both your brothers that are travelling and the family members that are still beside you :)
I wish your family all the best. May your brothers find what they are looking for!