As a rail enthusiast I will give my opinion. These trains should be there from katihar junction
Kir-pune
Kir-csmt
Kir- surat
kir - Hybd
Kir-...
more... Smvt
Kir- Mas
If there is some group at Katihar who can give these advises to concerned officials should include these demands.
In future purnea will be having domestic airport and katihar is already a major junction. Nothing more is required for a particular region.