Nepal Physical Society (NPS)is the biggest organization of Nepali physicists. Most of the professors, teachers and students are associated with it. NPS has it's own website and various discussion forum which are as follows.
Homepage of NPS: http://nps.org.np/
Google Group : https://groups.google.com/forum/?fromgroups#!forum/nps_nepal
Facebook Page : https://www.facebook.com/pages/Nepal-Physical-Society/117652149873

Patan Multiple campus MSC physics: Patan college is the largest college on the basis that largest number of students enroll this college in Nepal and students of this college are conducting a group which link is  https://www.facebook.com/groups/Pmcmsc/

Amrit College is another science in Nepal and I found two facebook group from that college divided as their acedemic year .
https://www.facebook.com/groups/mscphyascol2/
https://www.facebook.com/groups/mscphysicsascol/


There is a group from GoldenGate college also. you can meet them here
https://www.facebook.com/groups/206412389411659/

Central Department of Physics is the headquarter of physics of Tribhubhan University. The students of that college are also conducting a group of facebook.
https://www.facebook.com/groups/141698952558368/


There are also some other group which are not associated with college and created by physics lovers like
Physics group 
Physics Discussion 
National Academy of Physics

There are other website to help student of physics.
Dr Binil Aryal in conducting a blog of astrophysics. You can visit that blog here
There is another useful blog by Nabin Malakar. His blog contains important news updates, information  and  tips and tricks related with physics. His blog URL is http://www.nabinkm.com
. for Nepali Chemists there is useful  blog. you can visit it here.  www.nepachem.blogspot.com.

I  am afraid that i could not collect all the blogs and groups. If you are not listed here please leave comment. I will publish as soon as possible.