You can book an extra coach that can be attached to regular trains. But these special coaches cannot be attached to certain trains due to operational restrictions.
Application of such coaches must reach the Chief Passenger Transportation Manager in the Zonal Headquarters of the tour originating station, atleast 30 days in advance, including full details such as destination, the specific train name, any halts needed etc. Also an initial payment of Rs.10000 as security deposit to be made to Station Manager of the Originating station.