They will use NDLS for commuter and as well premium train traffic.
There are many proposed terminals in the Delhi :
1. DSJ for (North West , South and Through trains towards ROK-LDH/BTI)...
more...
2. IGI/Bijwasan for trains towards Rajasthan and Gujarat (it may hold some premium trains as well for passengers who wants to directly connect with the airport)
3. NDLS for VBs , Semi Highspeed , Premium trains on Indian railways as well as some commuter trains for CP CBD.
4. Holambi Kalan for North Bound trains (but ideally it should be scrapped , it falls in the remote northern part of the city and connectivity is an issue.)
5. ANVT : East bound trains
6. Delhi : East-West , North-East passing by trains , commuter and intercity trains towards north and east and uttrakhand...
7. DEE : For ROK/BTI/SGNR bound trains ..