Connectify and Galaxy Grand duos android 4.2.2 hotspot connectivity issue
I got the solution finally. It so happens that there are 2 modes i.e the 2GHz and the 5GHz in a wifi adapter and the my mobile works in just one of them i.e. the 2 GHz mode. 

All we need to do is change the mode of operation of our system or hotspot host.

For that: 


Go to Device Manager.
Go to Network Adapter.
Acc. to my system I right clicked on the adapter by the name of
Intel Centrino Advanced N-6235 and went to properties
Go to Advanced. For those who want to know how the adapter
properties look like by hit and trial here is a snapshot of the
advanced tab of properties.





Choose "Preferred Band" and change it to 5.2GHz.
Click Okay and restart your hotspot the job is done !