Agree with you 12coach rakes needed which is 320 seats addition in ACC making 850 seats or 60% capacity augmentation. Capacity addition should be in organic manner then inorganic manner to 16C 100+% at a time will lead you overcapacity.
The VB will which require 12 Coach rakes
1. Coimbatore Chennai
2. Madurai Chennai
3.Kasargod...
more... TVM( Manguluru)
4. Dehradun New Delhi
5. Patna Howrah
6. Kacheguda Yesvantpur.