First buy a WL ticket of any train and then go to booked ticket history after selecting that WL ticket go for Opt for Vikalp option afterwards you have to choose from the list of train running between both station.
A person can opt for maximum 7 trains at a time subject to availability for the train running between both Station and it should be within 12 hours of actual departure.
I had choosen this train for getting benefit of ATAS.
Yes...
more... I have got an SMS immediately when chart has been prepared for original train (Poorva Exp)
The msg was like " PNR 25590***** provided accommodation in new Train No 12260 from NDLS to SDAH under ATAS scheme. Please check PNR Enquiry for coach, seat and boarding info"
Hope this information will help other too. Thanks.