I think agartala and capitals of the north eastern states need a rajdhani. Another point is that the no of rajdhanis to dibrugarh can be reduced and one of them can be terminated at guwahati .patna can also be eligible for another rajdhani , but that would lead to more congestion in the kanpur new delhi section so it will have to avail the route through lucknow and moradaradwhich is not the 'fastest' route but can atleast be experimented.